Engine Exhaust Emissions Research Articles

Assessment of trade-off, exergetic performance, and greenhouse gas impact-cost analysis of a diesel engine running with different proportions of TiO2, Ag2O, and CeO2 nanoadditives

In this study, the effects of adding different proportions of TiO2, Ag2O, and CeO2 nanoparticles to a three-cylinder, water-cooled, four-stroke, direct injection diesel engine on engine performance and exhaust emissions are experimentally investigated. The experiments are conducted at four different engine loads (10, 20, 30, and 40 Nm) and a constant engine speed (1800 rpm). TiO2, Ag2O, and CeO2 nanoparticles are added to the diesel fuel at concentrations of 50 and 75 ppm each. The test fuels used in the study are as follows: D100, DTi50, DTi75, DAg50, DAg75, DCe50 and DCe75. Using the experimental results, analyses of energy, exergy, sustainability, greenhouse gas (GHG) emission impact, and cost are performed. The experimental results reveal that the use of nanoparticles in diesel fuel reduces BSFC. The highest reduction in BSFC is achieved with DTi75 fuel, averaging 9%. Additionally, DTi75 fuel shows an average increase of 19% in NOx emissions compared to D100 fuel, while smoke emissions decrease by an average of 30%. The highest average increase in exergy efficiency compared to D100 fuel is obtained with DAg50 fuel (5.6%), followed by DTi75 fuel (5.3%). The addition of nanoparticles to diesel fuel also leads to an increase in GHG emissions. Compared to D100 fuel, the highest average contribution to GHG emissions increase is shown by DTi75 fuel (12%), while the lowest average contribution is observed with DAg50 fuel (4%).

Optimization of bio-oil blends in gasoline engines for enhanced efficiency and emissions reduction: A response surface methodology approach

The escalating global demand for energy, coupled with growing environmental concerns, necessitates the exploration of cleaner fuel alternatives. Bio-oil, characterized by its renewability and potential to mitigate emissions, has emerged as a viable candidate. This study focuses on optimizing bio-oil concentrations in gasoline engines to enhance operational performance while reducing pollutant emissions. Employing Response Surface Methodology (RSM), the investigation evaluates the effects of varying bio-oil-gasoline blends on engine performance metrics, fuel consumption, and exhaust emissions. Experiments were conducted using a single-cylinder, four-stroke gasoline engine with bio-oil concentrations of 5 %, 10 %, and 15 %. The results identified an optimal bio-oil concentration of 9–10 % and an injection pressure range of 220–230 bar Under these conditions, the Brake Thermal Efficiency (BTE) increased by 31.1 %, and the Brake Specific Fuel Consumption (BSFC) was reduced to 274.4 g/kWh, indicating enhanced fuel efficiency. Emissions analysis demonstrated a 45 % reduction in carbon monoxide (CO) and a 50 % decrease in hydrocarbon (HC) emissions at a bio-oil concentration of 10 %, with nitrogen oxide (NOx) emissions controlled below 110 ppm at higher bio-oil levels. These findings suggest that the optimized bio-oil blend significantly improves engine efficiency while minimizing environmental impact, positioning bio-oil as a promising solution for cleaner and more sustainable energy production.

Comprehensive investigation of the effects on fuel, performance and emission properties of modify fuel blends addition of graphene nanoplatelets to ternary fuel blends (diesel, waste cooking biodiesel, and butanol) in a diesel engine

Development of alternative fuels from organic waste for the applications in CI diesel engines is an important research area for a sustainable energy future. In CI diesel engines, binary and ternary fuel blends can be prepared by blending fossil diesel fuel with biodiesel and alcohols. In recent years, various fuel blends have been improved with different metal or non-metal nanoparticles. In this work, non-metallic Graphene Nanoplatelets (GNPs) were added to ternary fuel blends, followed by the characterization of the prepared samples. Subsequently, an investigation was conducted to examine their effects in engine performance and exhaust emissions. In this study, ternary blends were prepared by adding biodiesel obtained from the recycling of waste cooking oils and 10%, 15%, and 20% butanol to diesel fuel. Subsequently, 50 ppm of GNPs were added to these blends. Initially, the chemical properties of all fuel blends, such as cetane index, calorific value, density, and kinematic viscosity, were analyzed. Additionally, TG, DSC, FTIR, UV-VIS, and GS-FID characterizations were conducted for all fuel samples. Afterwards, engine performance, combustion characteristics, and exhaust emissions were performed. A total of 7 distinct fuel samples were employed in the engine testing procedure, wherein the engine was operated at 2 different speeds and 5 engine loads. The experiment results indicated that the lowest BSFC values occurred in diesel fuel under all conditions. With the addition of GNPs to the ternary fuels, the BSFC value decreased by an average of 1.11% at 1500rpm and 1.89% at 2000 rpm for all loads. Upon analysis of BTE values, it was revealed that diesel fuel had the greatest BTE value. The incorporation of GNPs into the ternary blends resulted in an average enhancement in BTE values of 1.40% at 1500rpm and 2.60% at 2000 rpm at all loads. The examination of the in-cylinder pressure and heat release rate indicated that the incorporation of GNPs led to a little decrease in the duration of the ignition delay. In the examination of NOx emissions, the inclusion of GNPs resulted in an average increase in emissions of 9.89% at 1500rpm and 5.37% at 2000 rpm at all loads. Furthermore, when analyzing CO2 emissions, with the exception of non-load conditions, the incorporation of GNPs resulted in an average rise of 3.10% in CO2 emissions at 1500rpm and 3.55% at 2000 rpm at all load conditions. The study revealed that fuel samples exhibited qualities close to those of diesel fuel standards.

Evaluation of Fuel Consumption and Exhaust Emissions in a Single Cylinder Four-Stroke Diesel Engine Using Biodiesel Derived from Chicken Waste with Additives

Biodiesel is a renewable, locally generated fuel made from vegetable oils, trans fats, or recycled restaurant grease for use in diesel automobiles and other diesel-powered equipment. The physical qualities of biodiesel are comparable to those of petroleum diesel. Biodiesel is used in compression-ignition engines in the same way as petroleum diesel. Biofuel can be made from biomass, but according to the Indian National Policy on Biofuels, biofuel extraction from edible oils is not permitted because it would result in a massive increase in consumer goods prices and perhaps lead to product scarcity. Hence, there is a need to search for alternative biofuel so that it does not affect our nation's national policy. Recently there has been a drastic increase in the consumption of chicken grown in farms. There is a huge problem in disposing of their waste. One major difficulty in waste treatment is poultry manure, often known as slaughter waste. This waste is sometimes dumped on wastelands, roadsides, and the banks of rivers, lakes, and ponds. This creates more sanitary problems for society. According to polls, poultry feces begin to decompose in around three hours. The odor of butcher's waste causes a lot of pollution in the air, as well as an increase in the density of bacteria in the atmosphere. Measures have been taken by the government for the safe disposal of these wastes. One of the major ways of disposal is to recycle this chicken slaughter waste in a useful manner so that it can serve society in a positive way. This could be done by converting this waste into fuel through various processes such as rendering, hydrolysis, extraction, acid esterification, alkaline transesterification, and finally by the extraction process. This produced fuel could be blended with existing diesel in varying concentrations and used in diesel engine-powered vehicles. In this work, the fuel is extracted from the chicken waste and blended with pure diesel and an Al2O3 additive in various proportions. These combinations are then tested on a single-cylinder diesel engine for fuel consumption and emission analysis. The results exhibited an overall better performance when compared to pure diesel.

Experimental assessment of catalytic biofuel effect on performance and exhaust emission of diesel engine

The present experiment is to analyze the effect of blended biodiesel of chicken fat CF10 (10% chicken fat and 90% diesel), waste cooking oil WC10 (10% waste cooking oil and 90% diesel), and combined chicken fat with waste cooking oil CF&WC10 (5% chicken fat + 5% waste cooking oil and 90% diesel) on the performance of diesel engine. The experiment is conducted at a constant compression ratio of 17, mixing 50 ppm alumina alfa (Al2O3-α) catalyst nanoparticles in each blend. The performance of biodiesel is analyzed at 25%, 50%, 75%, and 100% load conditions and is compared with pure diesel. The results show that the brake torque (BT) and brake power of CF&WC10 were found to be 22.48 Nm and 3.58 kW at full load conditions. However, the indicated thermal efficiency and BTE of CF&WC10 are at full loading conditions of 52.45% and 26.78% respectively. Because the supply of A/F ratio is 18.81, at full load condition and also lowering the brake specific fuel consumption up to 0.32 kg/kWh. Therefore, optimization of both performance and exhaust emission of an engine depends on BTE and NOx as well as HC emissions. Hence, from the emissions reduction point of view, CF&WC10 has lower emissions while achieving brake thermal efficiency similar to diesel fuel. The novelty of research shows CF&WC10 leads to enhanced performance of diesel engine compared to pure diesel fuel.

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.

Comparative analysis of spark ignition engine performance using RON 95 and RON 100 gasoline fuels

Most of the vehicles used by Malaysians have engines that only require petrol RON 95 to power the engine. However, many people claimed that utilising RON 100 instead of RON 95 for their vehicles will improve engine performance. Furthermore, many people speculate that using oil with a low octane level in an engine with low performance will affect the engine's performance. The goal of this research is to analyse and compare the engine performance and emissions on a spark ignition engine using gasoline RON 95 and RON 100. In this study, a single-cylinder four-stroke engine running with RON 95 and RON 100 has been tested on an engine dynamometer to evaluate the brake power, torque, specific fuel consumption, and exhaust emissions. The emissions from the engines have been determined using a gas emissions analyser. The outcomes of the experiment have been analysed based on engine torque, braking power, and exhaust emissions. Based on the analysis, torque, brake power, and emissions data obtained from the dynamometer engine, RON 100 has a higher and smoother performance than RON 95.

Determination of the effect of low concentration titanium dioxide nano fuel additive in biodiesel on performance and emissions

In this study, the effect of nanoparticle addition into rapeseed methyl ester (R0) produced by the transesterification method on engine performance and emissions was experimentally investigated. Titanium dioxide was used as a nano fuel additive and was added to the test fuels at rates of 50 ppm (RTi50) and 75 ppm (RTi75) using an ultrasonic mixer. The effect of titanium dioxide on engine performance and exhaust emissions was experimentally determined by taking advantage of its photocatalysis effect and chemical reaction accelerator properties. Additionally, titanium dioxide additive reduced the viscosity and density of biodiesel fuel, resulting in higher micro explosion. According to the test results carried out at 4 different engine loads, brake specific fuel consumption decreased by 7.51% and 8.62% in RTi50 and RTi75 fuels compared to R0 fuel. Brake thermal efficiency increased by 2.47% and 6.21%, respectively. The improvement in combustion achieved by the nano additive increased the conversion of CO emissions into CO2, increased NOX emissions, reduced smoke emissions and caused more complete combustion products to come out of the exhaust.

Numerical Analysis of the Effect of Ethanol-Gasoline Blends on a Single-Cylinder Spark-Ignition Engine Performance and Emissions

— With the rapid increase in the number of vehicles fueled by gasoline plying on the roads, there has been a rising need in the search for alternative fuels, which are more environmental friendly in order to reduce the amount of vehicular exhaust emissions. This can be achieved by using blended mixtures of gasoline with alcoholic fuels among which, ethanol is found to be most suitable due to its easy availability, low costs, safety and low impact on the engine performance. This study aims to investigate the performance of a single-cylinder, four-stroke spark-ignition engine using different ethanol-gasoline blends, namely E0, E10, E20 and E30. The engine's torque, brake power, brake thermal efficiency, brake-specific fuel consumption, and exhaust emissions were analysed using numerical simulation. Results revealed that raising the proportion of ethanol in the fuel mixture resulted in reduced brake power and torque upto 16% as a result of decrease in calorific value of the mixture. The engine's brake thermal efficiency decreased by upto 3% while the brake-specific fuel consumption increased upto 12% with increase in ethanol concentration. Exhaust emissions, including NOx and HC, were found to be influenced by engine speed, with NOx emissions increasing and HC emissions decreasing as speed increased. The study also revealed that increasing ethanol concentration in the fuel resulted in reduced engine exhaust emissions by upto 47% and 10% for NOX and HC emissions respectively. The study concluded that among all the blends used, optimum performance was obtained for E30 blend with reduction in exhaust emissions but at the expense of slight reduction in engine performance.

A full-scale CFD model of scavenge air inlet temperature on two-stroke marine diesel engine combustion and exhaust emission characteristics

Most ships in the maritime transport sector are equipped with large two-stroke marine diesel engines in their propulsion systems. Therefore, ensuring stable and long-term operation of these engines is crucial to maintaining freight transportation. The design of the ship's machinery, particularly the diesel engine, is a crucial step in achieving this goal. Computational Fluid Dynamics (CFD) tools can be used to achieve this goal. This article presents a full-scale CFD study on the effect of different scavenge air inlet temperatures (300, 312, 330 and 340 K) on the combustion process and generation of exhaust emissions in a two-stroke marine diesel engine using ANSYS Forte software. Regarding the cylinder pressure, the presented model agrees well with experimental data. The maximum cylinder pressure decreases as the scavenge air inlet temperature increases, whereas the maximum cylinder temperature increases as the scavenge air inlet temperature increases. The maximum NOX, CO and UHC emission values are calculated to be 2256.5, 20375.8 and 3743.9 ppm, respectively, at a scavenge air inlet temperature of 340 K. Due to the higher combustion temperature caused by the increasing scavenge air inlet temperature, it is observed that the exhaust emission levels increase.

Modelling and experimental analysis of Aero-Engine performance and exhaust emission characteristics Fueled with green fuel blends

This study aims to assess the impact of using green fuel in place of biodiesel on the performance and exhaust emissions of air-breathing engines. GasTurb 13 is utilized to forecast the engine’s performance (kingTech 180 k turbojet engine). Catalytic deoxygenation of vegetable oils produces green diesel, offering an alternative to biodiesel. Physiochemical properties of GD blends (PME30GD20, PME20GD30, PME10GD10) were analyzed, and GasTurb-13 software predicted engine performance and emissions, validated with experimental data. The results show that GD10PME10 exhibited higher density (767.6 g/m3) than pure green fuel, while viscosity dropped by 53.85 % compared to PME. GD outperformed Jet-A1 by 0.74 % in heating value, with GD10PME10 having the highest at 42.63 MJ/kg. Engine performance measures included thrust, mass fuel flow, thrust-specific fuel consumption, and exhaust gas temperature. GD10PME10 showed a 12.5 % thrust increase and the lowest TSFC (95 g/kN.s) at 80,000 RPM compared to Jet-A1. GD20PME30 achieved the lowest EGT (550 °C) at the same RPM. Regarding emissions, GD20PME30 emitted the lowest CO (100,000 RPM, 150 ppm) and 0.5 % less CO2 (90,000 RPM) than Jet-A1. GD10PME10 produced the lowest NOx (12.5 ppm) at maximum speed, while Jet-A1 emitted the least NOx (7.5 ppm) at 120 k RPM. Overall, the data suggested that green fuel might increase the physiochemical properties of biodiesel blends, hence improving the fuel’s capacity to burn more effectively in aero-engines.

A Comprehensive Review on the Hydrogen–Natural Gas–Diesel Tri-Fuel Engine Exhaust Emissions

Natural gas (NG) is favored for transportation due to its availability and lower CO2 emissions than fossil fuels, despite drawbacks like poor lean combustion ability and slow burning. According to a few recent studies, using hydrogen (H2) alongside NG and diesel in Tri-fuel mode addresses these drawbacks while enhancing efficiency and reducing emissions, making it a promising option for diesel engines. Due to the importance and novelty of this, the continuation of ongoing research, and insufficient literature studies on HNG–diesel engine emissions that are considered helpful to researchers, this research has been conducted. This review summarizes the recent research on the HNG–diesel Tri-fuel engines utilizing hydrogen-enriched natural gas (HNG). The research methodology involved summarizing the effect of engine design, operating conditions, fuel mixing ratios and supplying techniques on the CO, CO2, NOx and HC emissions separately. Previous studies show that using natural gas with diesel increases CO and HC emissions while decreasing NOx and CO2 compared to pure diesel. However, using hydrogen with diesel reduces CO, CO2, and HC emissions but increases NOx. On the other hand, HNG–diesel fuel mode effectively mitigates the disadvantages of using these fuels separately, resulting in decreased emissions of CO, CO2, HC, and NOx. The inclusion of hydrogen improves combustion efficiency, reduces ignition delay, and enhances heat release and in-cylinder pressure. Additionally, operational parameters such as engine power, speed, load, air–fuel ratio, compression ratio, and injection parameters directly affect emissions in HNG–diesel Tri-fuel engines. Overall, the Tri-fuel approach offers promising emissions benefits compared to using natural gas or hydrogen separately as dual-fuels.

Pengaruh Modifikasi Permukaan Piston terhadap Emisi Gas Buang Motor Bakar Kapasitas 100 cc

Technological advances in motorized transportation are progressing rapidly, making motorized vehicles the main mode of transportation. The increasing number of motorized vehicles in society results in a significant increase in exhaust emissions. Combustion in vehicle engines is not always perfect, producing exhaust gases containing compounds harmful to human health, such as carbon monoxide (CO), hydrocarbons (HC), carbon dioxide (CO2), and nitrogen oxides (NOx). This study investigates the effect of variations in piston dome shape on exhaust emissions in a 100cc internal combustion engine using RON 90 fuel. The goal is to find the optimal compression ratio to produce cleaner exhaust emissions. The research data are presented in tabular form and analyzed using one-way ANOVA and graphs. The results showed a significant reduction in CO and HC emissions at all engine speeds (1000, 2000, 4000, and 5000 rpm) with variations in piston dome shape. The reduction in CO emissions ranged from 55.07% to 85.73%, while the reduction in HC emissions ranged from 54.14% to 86.10%. These results suggest that variations in piston dome shape can be an effective solution to minimize harmful exhaust emissions in internal combustion engines.

The Effect of Combustion Phase According to the Premixed Ethanol Ratio Based on the Same Total Lower Heating Value on the Formation and Oxidation of Exhaust Emissions in a Reactivity-Controlled Compression Ignition Engine

A compression ignition engine generates power by using the auto-ignition characteristics of fuel injected into the cylinder. Although it has high fuel efficiency, it discharges a lot of exhaust emissions such as NOX and PM. Therefore, there is much ongoing research aiming to reduce the exhaust emissions by using the technologies applied in this regard, such as PCCI, HCCI, etc. However, these methods still discharge large exhaust emissions. The RCCI method, which combines the spark ignition method and compression ignition method, is attracting attention. So, in this work, the objective of this study is to numerically investigate the effect of combustion phase according to the premixed ethanol ratio based on the same total heating value in-cylinder by changing the initial air composition on the formation and oxidation of exhaust emissions in the RCCI engine. The heating value of the premixed ethanol ratio varied from 0% to 40% based on the same total lower heating value in-cylinder in steps of 10%. It was assumed that the ethanol introduced into the cylinder through the premixing chamber was evaporated, and the initial air composition in the cylinder was changed and set. It was revealed that when the premixed ratio based on the same total lower heating value was increased, the introduced fuel amount into the crevice volume with advancing the start of energizing timing was decreased, which increased the peak cylinder pressure. In addition, the ignition delay was also longer due to the low cylinder temperature by the evaporation latent heat of the ethanol, which reduced the compression loss, so the IMEP value was increased. The rich equivalence ratio had a narrow distribution in the cylinder, which caused a reduction in cylinder temperature, so the NO formation amount was reduced. The ISCO value increased the increase in premixed ethanol ratio based on the same total lower heating value in-cylinder because the flame propagation of ethanol by combustion of diesel did not work well, and the CO formed by combustion was slowly oxidized due to the cylinder’s low temperature as a result of the evaporation latent heat of ethanol. From these results, the optimal operating conditions for simultaneously reducing the exhaust emissions and improving the combustion performance were judged such that the start of energizing timing was BTDC 23 deg, and the premixed ethanol ratio based on the same total lower heating value in-cylinder was 40%.

An Experimental Study using Diesel Additives to Examine the Combustion and Exhaust Emissions of CI Engines

An Experimental Study using Diesel Additives to Examine the Combustion and Exhaust Emissions of CI Engines

Intensification of valorization of cooked rice water through energy-efficient synthesis of drop-in biofuel (butyl levulinate): engine performance, emission profile, and environmental impact assessments.

For the first time, an energy-efficient and eco-friendly technology for the conversion of abundantly available kitchen waste, specifically waste cooked rice water (WCRW) to drop-in- biofuels, namely, butyl levulinate (BL), has been explored. The synthesis of BL was accomplished employing butyl alcohol (BA) and WCRW in an energy-efficient UV (5W each UVA and UVB)-near-infrared (100W) irradiation assisted spinning (120rpm) batch reactor (UVNIRSR) in the presence of TiO2-Amberlyst 15 (TA15) photo-acidic catalyst system (PACS). The optimal 95.81% yield of BL (YBL) could be achieved at 10 wt% catalyst concentration, 60°C reaction temperature, 80min time, and 1:10 WCRW: BA concentration as per Taguchi statistical design. Moreover, additional combination of different PACS such as TiO2-Amberlyst 16, TiO2-Amberlyst 36, and TiO2-Amberlite IRC120 H rendered 86.72% YBL, 90.04% YBL, and 93.47% YBL, respectively, proving superior efficacy compared to individual activity of the acidic catalysts and photocatalysts. The heterogeneous reaction kinetics study for TA15 PACS suggested Langmuir-Hinshelwood model to be the best fitted model. A significant 63.33% energy could be saved by UVNIRSR as compared to conventional heated reactor at the optimized experimental condition using PACS TA15. An overall alleviation in environmental pollution with 59.259% reduction in GWP, 15.254% decline in terrestrial ecotoxicity, 18.238% diminution in marine ecotoxicity, 17.25% decrease in ozone formation affecting human health, 5.865% reduction in human non-carcinogenic toxicity, 18.65% diminution in ozone formation affecting terrestrial ecosystem, 55.17% significant decrease in terrestrial acidification, and 25.619% mitigation in fresh water ecotoxicity could be observed. Furthermore, BL-biodiesel-diesel blends (3% BL, 7% biodiesel, and 90% diesel) exhibited significant reduction (25.45% and 36%, respectively, for CO and HC) in harmful engine exhaust emissions demonstrating environmental sustainability of the overall process.

Effects of Castor and Corn Biodiesel on Engine Performance and Emissions under Low-Load Conditions

Growing concerns over resource depletion and air pollution driven by the rising dependence on fossil fuels necessitate the exploration of alternative energy sources. This study investigates the performance and emission characteristics of a diesel engine fueled by biodiesel blends (B10 and B20) derived from castor and corn feedstocks under low-load conditions (idle and minimal accessory loads). We compare the impact of these biofuels on engine power, fuel consumption, and exhaust emissions relative to conventional diesel, particularly in scenarios mimicking real-world traffic congestion and vehicle stops. The findings suggest that biodiesel offers environmental benefits by reducing harmful pollutants like carbon monoxide (CO) and particulate matter (PM) during engine idling and low-load operation. However, replacing diesel with biodiesel requires further research to address potential drawbacks like increased NOx emissions and lower thermal efficiency. While a higher fuel consumption with biodiesel may occur due to its lower calorific value, the overall benefit of reduced contaminant emissions makes it a promising alternative fuel.

The impact of hydrogen injection pressure and timing on exhaust, mechanical vibration, and noise emissions in a CI engine fueled with hydrogen-diesel

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 CO2 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.

Hydrogen enriched LNG fuel for maritime applications – A life cycle study

This study evaluates the engine performance and life-cycle emissions of hydrogen enriched LNG as a pragmatic solution to more rapidly introducing hydrogen as marine fuel, while waiting for pure hydrogen fuel infrastructure to be built. Engine experiments in a 4-stroke marine diesel engine operating with a spark-ignited pre-chamber ignition system were conducted, and a wide range of engine exhaust emissions measurements including CH4, N2O, H2, and particulate matter (black carbon emission evaluation) were recorded at varying engine loads. The fuel compositions ranged from pure LNG operation to pure hydrogen operation and also included pure conventional diesel fuel oil for comparison. The research methodology integrates engine tests with a full well-to-wake life-cycle assessment (LCA). The impact of using 39.6% hydrogen by energy fraction in natural gas reduced GHG emission by 37.8% on a life-cycle basis at 50% engine load, which could mean a significant reduction of GHG emissions.

Investigation of the effect of ether oxygenated additives on diesel engine performance, combustion, and exhaust emissions - An experimental approach

Conventional energy sources, including diesel and petrol, are decreasing day by day, while their reserves are limited. However, it is difficult to find alternative fuels to replace them. Hence, to fulfill the growing energy demand and reduce environmental emissions, it is vital to find a wide variety of oxygenated compounds to conventional diesel fuels that show low emission potential from transport engines. In this research, we investigated diesel engine performance, combustion, and exhaust emissions with the addition of 10 %, 15 %, 25 %, and 30 % of three different oxygenated blends, including Diethylene Glycol Dimethyl ether (DGM), Di-n-Butyl Ether (DBE), and Tripropylene-Glycol Monomethyl ether (TPGM). This paper presents the brake-specific fuel consumption (BSFC), Brake Thermal Efficiency (BTE), Brake Mean Effective Pressure (BMEP), and Brake Specific Energy Consumption (BSEC) for these fuel blends. The generated emissions of carbon dioxide (CO2), Carbon Monoxide (CO), and nitrogen oxide (NO) were quantified for four different engine speeds of 1500, 1800, 2000, and 2400 rpm for neat (100 %) oxygenated blends. This research also shows the in-cylinder pressure and heat release rate (HRR) of these three oxygenated blends. The outcome of this paper will help future researchers to develop automobiles and vehicles for oxygenated blends with conventional fuels.