Engine Emission Characteristics Research Articles

Influence of phenolic antioxidant additives on performance and emission characteristics of diesel engine fuelled with Jatropha biodiesel: A sustainable hybrid model using RSM and ANFIS

This study aimed to assess the inclusion of antioxidant diphenylamine (DPA) to a Jatropha biodiesel (B30) blend to affects engine performance and exhaust emissions. In this research, three fuel blends has been utilized: diesel, B30, and 100 ppm of antioxidant diphenylamine is added to the B30 blend referred to as B30 + DPA100. A Response Surface Methodology (RSM) has been employed to analyze experimental data, resulting in the development of a regression equation. Additionally, an Adaptive Neuro-Fuzzy Inference System (ANFIS) has been employed to assess and verify the consistency of the developed model. The results from the experiments revealed that the inclusion of the antioxidant had a notable impact on reducing NOx emissions with only a slight effect on brake thermal efficiency (BTHE). Specifically, B30 + DPA100 showed a 7.48 and 15.53% decrease in average NOx emissions, while the average BTHE experienced a modest 0.78% decrease and a 2.67% increase compared to diesel and B30 biodiesel blend, respectively. The Brake Mean Effective Pressure (BMEP) of B30 + DPA100 has been found to be 3.91% and 1.3% higher than diesel and B30, respectively. The Brake Specific Fuel Consumption (BSFC) was 8.68% lower than B30 but 1.49% higher than diesel. Overall, these findings suggest that B30 + DPA100 can be used in diesel engines without modification, offering reduced NOx emissions.

Experimental and numerical investigation of combustion, performance and emission characteristics of a GDI engine using hydrogen-water complementary regulation

In this paper, the coupling effect of water injection and hydrogen enrichment on combustion, performance and emission characteristics of a GDI engine was experimentally and numerically investigated. The engine speed is maintained at 1300 rpm with an excess air/fuel ratio of 1.0. The hydrogen energy substitution ratio is set to 15%. Water/fuel ratio is set to 0.2 and 0.4. The spark timing is kept fixed at −25 °CA ATDC. Results indicated that there exists competing effect between water injection and hydrogen enrichment. Water injection works as a reactivity suppressor, which slows down the overall flame propagation and deteriorates combustion. Whereas, hydrogen enrichment works as a combustion enhancer, which accelerates the combustion and improves the mixing of air-fuel mixture. The overall combustion speed, which is slowed down by water injection, can be largely recovered by hydrogen enrichment. In addition, a reasonable balance between the competing effects of water injection and hydrogen enrichment can make the combustion similar, meanwhile exhibits different emissions performance. Furthermore, the competing effect vanishes when the liquid water is completely vaporized. To some extent, hydrogen enrichment has a more lasting effect on combustion.

Performance, combustion and emission reduction characteristics of Metal-based silicon dioxide nanoparticle additives included in ternary fuel (diesel-SMME-iso butanol) on diesel engine

Biodiesel has long been recognized as a viable alternative energy source. In order to enhance the quality, and performance of biodiesel-diesel fuel blends while reducing air pollution from combustion, additives must be employed. The present research aims to focus on the addition of SiO2 novel nanoparticles (at a concentration of 30, 60, and 90 mg/L) in the ternary fuel (TF) blend (75% of Diesel+ 15% of Sea Mango Methyl Ester (SMME15) + 10% of iso-Butanol on a volume basis) to determine engine performance, combustion, and emission characteristics of a 1-cylinder, direct injection, liquid-cooled, diesel engine. In addition to this, a stability analysis for the prepared samples was also carried out as per the ASTM standard. From the investigation, it was observed that, when the nanoparticles mixed with ternary fuel (i.e., TFSi60), the brake thermal efficiency (BTE), In-cylinder pressure (ICP), and net heat release rate (NHRR) were improved by about 10.09, 17.4, and 10.73 % respectively. Whereas the brake-specific fuel consumption (BSFC) (19.13%) and hazardous pollutants like carbon monoxide (CO) (20.06%), unburnt hydrocarbons (UHC) (13.9%), nitrogen oxides (NOx) (11.3%), and smoke (11.2%) were significantly decreased. From the above observations, it is concluded that using a ternary fuel blend with nano additives improves engine performance and combustion while lowering toxic emissions.

Enhancing soot emission control and performance in biodiesel-powered diesel engine through Al2O3 nanoparticle

Abstract Interest in biodiesel as a diesel fuel substitute has increased due to the growing need for sustainable energy sources. The blends of biodiesel, such B20, have become more popular because they can lessen the need for fossil fuels and greenhouse gas emissions. The blends of biodiesel, however, may pose problems with emissions, performance, and combustion efficiency. The objective of this study is to investigate the effects of blending ethanol (C2H6OH) and aluminium oxide (Al2O3) into B20 biodiesel blend in order to improve engine performance. The study examines the effects of adding C2H6OH (5% of vol.) and Al2O3 (75 ppm) to the B20 biodiesel mix on its essential features and combustion. To fully assess the performance and emissions characteristics of the single cylinder diesel engine, experimental evaluations include a wide range of engine operating loads. The findings show that adding C2H6OH to the B20 blend increases its volatility and oxygen content, which promotes better ignition and combustion characteristics. Additionally, adding Al2O3 nanoparticles to the blend shows promise for improving combustion efficiency by enhancing fuel atomization and lowering soot emission. The synergy of adding both Al2O3 and C2H6OH to B20 significantly reduces CO, HC, and smoke levels of the diesel engine by 33.04, 28.13, and 12.88%, respectively. The results of this study offer important new information about how C2H6OH and Al2O3 additives might improve the B20 biodiesel blend's emissions performance and combustion efficiency, increasing the fuel's potential as a greener alternative for the transportation industry.

Advanced Numerical Analysis of In-Cylinder Combustion and NOx Formation Using Different Chamber Geometries

In diesel engines, emission formation inside the combustion chamber is a complex phenomenon. The combustion events inside the chamber occur in microseconds, affecting the overall engine performance and emissions characteristics. This study opted for using computational fluid dynamics (CFD) to investigate the combustion patterns and how these events affect nitrogen oxide (NOx) emissions. In this study, a diesel engine model with a flat combustion chamber (FCC) was developed for the simulation. The simulation result of the heat release rate (HRR) and cylinder pressure was validated with the experimental test data (the engine test was conducted at 1500 rpm at full load conditions). The validated model and its respective boundary conditions were used to investigate the effect of modified combustion chamber profiles on NOx emissions. Modified chambers, such as a bathtub combustion chamber (BTCC) and a shallow depth chamber (SCC), were developed, and their combustion events were analysed with respect to the FCC. This study revealed that combustion events such as fuel distribution, unburnt mass fractions, temperature and turbulent zones directly impact NOx emissions. The modified chambers controlled the spread of combustion and provided better fuel distribution, improving engine performance and combustion rates. The SCC (63.2 bar) showed peak pressure rates compared to the FCC (63.02 bar) and BTCC (62.72 bar). This study concluded that the SCC showed better results than other chambers. This study further recommends conducting lean fuel mixture combustion with chamber modifications and optimising fuel spray, such as by adjusting the fuel injection profile, spray angle and injection timing, which has a better tendency to create complete combustion.

Effect of fuel injection pressure on the performances of a CI engine using water-emulsified diesel (WED) as a fuel

BackgroundThe choice of energy sources is essential for sustainable development to combat different environmental issues caused by the consumption of fossil fuels. Though diesel engines are considered more efficient and reliable than other internal combustion engines, they emit different harmful pollutants which are detrimental to human health and the environment. Researchers are trying to find suitable alternative fuels for diesel engines with lower pollutant emissions and without much compromise in the efficiency of the engine. In this regard, water-emulsified diesel (WED) may be considered to be one of the most suitable alternative fuels. It is expected that the entire world will use electric vehicles in the long term. However, the complete replacement of IC engines in the near future is not feasible. In fact, different European countries have targeted to ban the use of diesel engine cars before the middle of the twenty-first century. Prior to that date, hybrid vehicles will be more popular and diesel engines will continue to play an important role. Hence, research involving improvements in diesel-operated IC engines is still relevant.MethodsAn experimental investigation was carried out using WED containing 10% water by volume as a fuel in a diesel engine at four different fuel injection pressures. The WED was prepared using an ultrasonicator.ResultsWith the increase of injection pressure, peak net heat release rate and in-cylinder pressure are found to have increased. Brake thermal efficiency is also found to have improved at higher injection pressure. The maximum efficiency was recorded when a WED at 210 bar of injection pressure is used, and it is about 3.3% higher than the maximum efficiency achieved when using normal diesel at the same pressure of fuel injection. At a higher load, neat brake-specific fuel consumption is found to be less compared to neat diesel, when only the amount of diesel contained in the emulsion as a fuel is considered. Maximum reduction in both NOx and smoke emission by using WED is recorded at 210 bar, and the average reductions are determined to be 32.6% and 51.9%, respectively.ConclusionsWED can be used as an alternative fuel for existing diesel engines without any retrofitting and with significant reduction in the emissions of pollutants compared to normal diesel fuel. It can also be concluded that at higher injection pressure, the combustion, performance and emission characteristics of compression ignition engines are improved when using emulsified diesel.

Experimental studies on performance, combustion, and emission characteristics of diesel engine powered with subabul seed biodiesel blends

ABSTRACT The increasing demand for fuel is due to industrialisation, transportation, and agricultural applications. The present research work exploits the potentiality of subabul seed biodiesel as a viable solution for diesel engine applications. Subabul crude oil was extracted from the subabul seeds through a mechanical pressing process. The transesterification technique was used to produce the subabul seed methyl ester (SSME). Different blends were prepared from subabul biodiesel such as SSME 10, SSME 20 and SSME 30 on a volume basis. It is found that SSME 20 was shown 3.26% higher BTE than SSME 10 at full load. Further, exhaust emissions like CO, HC and smoke were reduced drastically by 23.41%, 10.52% and 11.76% respectively at full load when compared to diesel. However, NOx emissions are 17% higher for the SSME20 than diesel. Further, Combustion characteristics of SSME20 such as HRR (72.68 J/ ˚CA), CP (71.94 bar) and ID (19˚) are closely competing with the diesel fuel.

Prospectus of hydrogen enrichment in internal combustion engines: Methodological insights on its production, injection, properties, performance and emissions

Hydrogen-enriched fuel has emerged as an important energy source for internal-combustion engines due to its cleanliness, continuous regeneration and efficient combustion. This review provides a synopsis of current developments in the field of hydrogen-enriched fueling for internal combustion engines. The purpose of this review article is to collect information on hydrogen enhancement in internal combustion engines and to provide a systematic viewpoint on their emissions and performance in various SI and CI engines. Firstly, the fundamentals of hydrogen enrichment followed by a full explanation of hydrogen production technologies as well as the characteristics of Hydrogen enriched mixtures of well-established IC engine fuels. In addition to this, the types of hydrogen injection systems are explained and the merits and demerits of each injection system are compared. Performance, emission and combustion characteristics of IC engines enriched with hydrogen are analyzed. Future research on hydrogen-enriched internal combustion engines has also been briefly outlined.

Performance analysis and emission characteristics of VCR diesel engine using palm stearin oil biodiesel as fuel

Abstract The increasing depletion of fossil fuels has prompted international efforts to search for diesel substitutes. One way to considerably reduce fuel shortages would be to use bio-derived fuels as replacements. Transesterification of edible or nonedible vegetable oils yields biodiesel, which is one example of a bio-origin fuel and a workable solution. Biodiesel’s characteristics are often more advantageous than those of diesel. One well-known example of a nonedible vegetable oil is palm stearin. In this work, we investigate the potential use of transesterified palm stearin methyl esters (PSME) as a substitute fuel. A rated compression ratio (CR) of 17.5 and 210 bar of fuel injection pressure were employed in the experimental investigations, which were carried out at a constant speed of 1500 rpm. Our main goals were to reduce emissions and improve engine performance. The evaluation parameters encompassed brake thermal efficiency (BTE), brake-specific fuel consumption (BSFC), and emission indices. It was observed that using PSME led to better performance and fewer emissions when compared to using conventional diesel, especially when the CR was 17.5. Increased BTE, decreased BSFC, lower air–fuel ratios, and decreased volumetric efficiencies were all correlated with higher CR. As a byproduct of palm oil, PSME shows promise as a seasonally and geographically specific feedstock for biodiesel production, providing benefits over conventional diesel fuels in terms of performance and the environment.

Performance prediction and multi-objective optimization for the Atkinson cycle engine using eXtreme Gradient Boosting

In this study, substantial efforts have been done to enhance both the economy and nitrogen dioxide (NOx) emission characteristics of an Atkinson cycle engine (ACE). The integrated simulation model was meticulously formulated and calibrated utilizing GT-Power software based on test data, and four machine learning (ML) models were developed to predict the performance of the ACE. On this basic, the improved multi-objective hybrid particle swarm optimization (IMHPSO) algorithm was proposed to conduct comprehensive optimization of ACE performance. The results highlight the superior prediction performance and generalization ability of the eXtreme Gradient Boosting (XGBoost) model, attaining an average coefficient of determination (R2) of 0.9978 and 0.9966 on the train and test sets, respectively. The IMHPSO algorithm exhibited efficient convergence, uniform distribution and rich diversity across five benchmark test problems, effectively mitigating issues related to local optima and premature convergence. The Optimal Brake Specific Fuel Consumption (BSFC) solution is chosen as the preferred optimized scheme and realizes significant reductions of 8.5 % for BSFC and 96.1 % for NOx emissions, which experiences a remarkable increase of over 1300 times in computational efficiency compared to the GT-Power model. These findings provide theoretical basis, data support and novel insights for multi-objective optimization of ACE performance.

Effect of pilot fuel quantity and fuel injection pressure on combustion, performance and emission characteristics of an automotive diesel engine

The work presented here experimentally investigates the effect of pilot quantity (PQ) on combustion, performance and emission characteristics of an automotive diesel engine. All the experiments were performed at max torque speed of the test engine (1600 rpm) and 75 % of full engine load. Three PQs under consideration are 10 %, 20 % and 30 % of total fuel mass per cycle while maintaining the fixed pilot as well as main injection timings. The minimum PQ (10 %) considered in the study was found sufficient to enhance the in-cylinder thermodynamic conditions before main injection starts. Also, fuel injection pressure (FIP) was maintained constant at 500 bar initially. Obtained results showed that the pilot injection mode with 30 % PQ reduced nitrogen oxide (NO) emission as well as brake specific fuel consumption (BSFC) by 21.87 % and 1.46 % respectively compared to reference single injection mode while smoke emissions were increased by 77.64 %. In order to curb this negative effect of higher smoke emissions offered by pilot injection, FIP was increased from 500 bar to 700 bar and similar experiments were repeated. The experimental results demonstrated that higher FIP significantly reduced smoke emissions as well as fuel consumption under all the considered pilot injection modes with acceptable rise of NO emission which was still considerably lower than reference single injection mode. For e.g., when FIP was increased from 500 bar to 700 bar in case of pilot injection mode with 30 % PQ, smoke emissions and BSFC were reduced by 26.40 % and 2.14 % respectively, while NO emission was increased by 6.30 %. Therefore, it can be said that combination of pilot injection and high FIP leads to overall improvement in performance and emission characteristics of the test engine.

Influence of ZnO and TiO2 nanoparticles on the performance, combustion and emission characteristics of diesel engine fueled with okra seed bio-diesel

Energy sector is demanding alternate fuel for conventional fuel to solve the problems like environmental pollution, Climate change and the exhaustion of fossil resources. Hence, the search of new fuel is paramount importance. This study aimed to identify a new fuel source from okra plants. Okra oil was extracted from okra seed and Okra biodiesel was prepared by transesterfication process. Okra bio-diesel was added with ZnO and TiO2 particles and its effects on diesel engine performance were examined. Performance study showed that B20 fuel exhibited the lowest BSFC of 0.34 kg/kWh and higher BTE of 33% among the biodiesel blends. Further, a lowest BSFC of 0.31 kg/kWh and BTE of 34% were observed for B20/50 ppm ZnO fuel. Combustion study showed that B20/50 ppm ZnO fuel exhibited the In-cylinder pressure and HRR of 71 bar and 54 kJ/°CA respectively. This is 5.9% and 8% increasing in In-cylinder pressure and HRR respectively, compared to B20 fuel. Emission study reported that the B20/50 ppm ZnO fuel showed the CO, HC and smoke release of 0.22 vol%, 40 ppm and 25 HSU respectively. This is 8.3%, 20% and 10.7% decrease in CO, HC, smoke release respectively, than B20 fuel.

Comparative analysis of compression ignition engines performance and emission characteristics devouring edible and nonedible oil biodiesel

AbstractThe globe is in search for an upgraded and compatible alternative of diesel to triumph over pollution and its limited availability issues. Researchers are using biodiesel from various edible and non‐edible oil sources to reduce environmental footprint of diesel. This article compares the performance and emission characteristics of diesel engines fueled by edible and non‐edible oil biodiesel. In this work, five biodiesels (methyl esters of microalgae, jatropha, karanja, soybean, and sunflower) are tested and transesterification is used to produce methyl esters to optimize their physiochemical properties. It is observed that all the properties lie in tolerance limits. To examine the compatibility of the proposed methyl esters two performance characteristics, brake thermal efficiency and brake specific fuel consumption are examined. Further, the emission characteristics such as nitrogen oxides, carbon monoxide, hydrocarbons, and carbon dioxides are investigated. To validate results the blend characteristics are compared to diesel. The relative analysis revels that the brake thermal efficiency is declined by 8.87% as compared to diesel whereas the brake specific fuel consumption is increased by 4.28%. The carbon monoxide and hydrocarbon levels are decreased by 7.32% and 20.56% whereas nitrogen oxides and carbon dioxide levels are increased by 7.47% and 4.80%, respectively. The analysis infers that microalgae biodiesel gives adequately better characteristics.

The combined effect of split fueling strategy and EGR on the combustion, performance, and emission characteristics of a CRDI biofuel engine

AbstractThe current research investigates the impact of a split fueling strategy combined with several flow rates of exhaust gas recirculation (EGR) on the combustion and emission characteristics of a diesel engine running on B20 waste cooking oil (WCO) biodiesel. A four‐stroke single‐cylinder common rail direct injection engine was employed for experiments. It operates with a B20 blend of WCO biodiesel at 600 bar pressure for varying pilot fueling conditions of 10%, 20%, and 30%. The B20 blend with 30% pilot fuel injection (B20P30) showed excellent performance and emission characteristics compared with B20 blend with 10% pilot fuel injection (B20P10) and B20 with 20% pilot fuel injection (B20P20). However, B20P30 had greater levels of nitrogen oxide (NOx) emissions than those by diesel. EGR discharge levels in 5% increments, ranging from 0% to 15% were introduced to address this issue. The experimental findings revealed that both cylinder peak pressure and heat release rate showed a reduction when the EGR flow rate was enhanced. The recirculation of exhaust gas into the combustion chamber led to a slight increase in the emission levels of hydrocarbon (HC), carbon monoxide (CO), and smoke, as well as a decrease in carbon dioxide (CO2). Nevertheless, the introduction of EGR significantly decreased NOx emissions by 22.94%, 35.05%, and 47.96% for EGR flow rates of 5%, 10%, and 15%, respectively, when compared with the engine operating without EGR. Overall, the two‐stage fueling strategy, B20P30 blended with 10% EGR corroborated to be beneficial in reducing NOx emissions with minimal performance penalties. Although there was a slight uptick in certain emissions, the overall trade‐off between emission reduction and performance was favorable. The culmination of this study is targeting the objectives of sustainable development goal 7 (clean energy) and goal 13 (climate action) to be achieved by 2030.

Effect of Di-tert Butyl Peroxide on Diesel Engine Performance Fuelled by Biodiesel Blends

This study is motivated by the fact that the vegetable oils are being considered as the fuel of the future for the internal combustion engines, especially the compression ignition engines which are working with diesel as fuel. Different approaches for using the vegetable oils in CI engines as fuel are either to modify the oils to match with that of diesel to run successfully with these oils. Fuel additives are compounds formulated to enhance the quality and efficiency of the fuels used in motor vehicles. There are several benefits associated with the use of fuel additives. Di-tert butyl peroxide (DTBP) is effective for enhance the quality and efficiency of the fuels used in CI engine. The investigation was to check the feasibility of di-tert butyl peroxide as an additive in different blends of diesel and jetropha bio-diesel on engine performance. The short-term tests on an unmodified diesel engine were conducted using the bio diesel and di-tert butyl peroxide blends (0, 10, 20, 30, 40, 50, and 100 per cent and 0, 0.5, 1.0, 1.5, 2.0, 2.5 per cent) with diesel. The engine performance and emission characteristics were measured during the short-term test. In all types of fuel, with increased percentage of load, brake specific energy consumption (BSEC) of the engine was observed to be decreased, on the other hand brake thermal efficiency, fuel consumption rate, sound level (db.), exhaust temperature, and the engine exhaust emissions like CO2, CO, HC and NOx was increased, respectively.

Experimental Investigation of Engine Characteristics Fuelled with Emulsified and Nano Emulsified Citrus Limon Seed Biodiesel

The exploration and advancement of alternative fuels serve as catalysts for innovation in energy technologies, fostering economic growth and offering sustainable solutions for transportation and industry. The process of emulsifying lowgrade diesel fuel enhances the atomization and mixing of the fuel with air, resulting in improved combustion efficiency, decreased emissions, and enhanced fuel efficiency. The introduction of nanoparticles into the emulsion results in an increase in the surface area of the fuel droplets, leading to enhanced atomization and improved combustion efficiency. The enhanced dispersion of particles in the air facilitates improved interaction, leading to decreased emissions of nitrogen oxides and particulate matter, contributing to the promotion of environmental sustainability. This study examines the performance and emission characteristics of a single-cylinder diesel engine when biodiesel derived from citrus limon seeds is combined with emulsified citrus limon seed biodiesel and nano-emulsified biodiesel. The nECLB had 2.57–4.2% braking thermal efficiency above the ECLB. Specific fuel consumption was 7.8% to 13.4% lower for the nECLB than the ECLB. The nECLB emitted 8.5% less HC and 21% less CO than the ECLB. When utilising base diesel, nECLB reduced nitrogen oxide and smoke emissions by 50%–65% and 0.5%–1.5%, respectively

Experimental and computational study on the effects of exhaust gas recirculation on thermodynamics, combustion and emission characteristics of a diesel pilot ignition natural gas engine

This study investigates the impact of diesel pilot ignition (DPI) natural gas (NG) engines on combustion and emission characteristics across various exhaust gas recirculation (EGR) volumes.

Study of the influence of adding Al2O3 nanoparticles to biodiesel on the performance and emissions characteristics of a diesel engine

The use of biodiesel in compression ignition (CI) engines has great potential to reduce emissions and the dependence on fossil fuels. However, the complete adoption of biodiesel in CI engines is limited by several drawbacks. A promising solution to these problems is the addition of nanoparticles to biodiesel or diesel-biodiesel blends. Hence, this paper studies the impact of adding aluminum oxide (Al2O3) nanoparticles on the performance and emission characteristics of a diesel engine running on biodiesel and a mixture of diesel and biodiesel. Al2O3 nanoparticles were added at concentrations of 50, 100 and 150 ppm to biodiesel (B100) and a mixture of 50 % biodiesel and 50 % commercial diesel (B50). The results indicated an increase in fuel conversion efficiency and a reduction in specific fuel consumption. The highest fuel conversion efficiency was 26.5 % for B50 with 100 ppm of Al2O3, indicating an improvement of around 28.6 % compared to diesel fuel (B0). In general, CO emissions were reduced with the addition of nanoparticles, with a maximum reduction of 42.8 % for B100 with 50 ppm Al2O3 compared to B0. The highest reduction in NOX emissions was 30.3 % for B50 with 100 ppm Al2O3 compared to pure diesel B0.

Effect of steam addition on the combustion, performance and emissions characteristics of an HCCI diesel engine

Effect of steam addition on the combustion, performance and emissions characteristics of an HCCI diesel engine

Comparative analysis of various nanomaterials mixed with WCO biodiesel on CI engine’s performance and emissions

The experimental investigations of performance and emission parameters of a compression ignition (CI) engine run by waste cooking oil (WCO) biodiesel dispersed with nanomaterials. The nanomaterials, Cerium oxide, Magnesium oxide, and Aluminium oxide of 30 ppm and 40 ppm dosages are mixed with the 20% of WCO biodiesel and diesel using an ultrasonicator. The performance and emission parameters are investigated by running the CI engine at constant speed for different loads. Based on the conducted experiments, it has been observed that the improvement in performance emission characteristics of CI engines is due to the addition of Cerium oxide, Magnesium oxide, and Aluminium oxide nanomaterials at 30 ppm and 40 ppm dosages of 20% WCO nanoparticles compared with that of diesel. It can therefore be concluded that adding nanomaterials in higher doses enhances CI engine performance and emissions.