Engine Emission Characteristics Research Articles

Effect of Injector Type and Intake Boosting on Combustion, Performance, and Emission Characteristics of a Spray-Guided Gasoline Direct Injection Engine—A Computational Fluid Dynamics Study

<div>In general, GDI engines operate with stratified mixtures at part-load conditions enabling increased fuel economy with high power output, however, with a compensation of increased soot emissions at part-load conditions. This is mainly due to improper in-cylinder mixing of air and fuel leading to a sharp decrease in gradient of reactant destruction term and heat release rate (HRR), resulting in flame quenching. The type of fuel injector and engine operating conditions play a significant role in the in-cylinder mixture formation. Therefore, in this study, a CFD analysis is utilized to compare the effect of stratified mixture combustion with multi-hole solid-cone and hollow-cone injectors on the performance and emission characteristics of a spray-guided GDI engine.</div> <div>The equivalence ratio (<i>ϕ</i>) from 0.6 to 0.8 with the constant engine speed of 2000 rev/min is considered. For both injectors, the fuel injection pressure of 200 bar is used with 60° spray-cone angles. For lean boosting conditions, intake pressures of 1 bar, 1.2 bar, and 1.4 bar are maintained for 0.8 equivalence ratio cases for both injectors. Results from the CFD analysis are compared with those of the available experimental results with good agreement. Analyzing the results, naturally aspirated and intake boosting conditions for <i>ϕ</i> of 0.8, mixture distribution and flame propagation for the multi-hole solid injector are better than hollow-cone injector. Also, for the <i>ϕ</i> of 0.8, naturally aspirated mode, the soot emissions by the hollow-cone injector are higher by about 90%, and the NO<sub>x</sub> emissions are higher by about 19% compared to that of the multi-hole solid-cone injector. Under boosted intake pressure conditions, for the hollow-cone injector, the soot emissions are higher by about 97%–99%, and NO<sub>x</sub> emissions are higher by about 7%–6% compared to the multi-hole solid-cone injector. Also, HC and CO emissions are considerably lower for the hollow-cone injector than that of the multi-hole solid-cone injector.</div>

A comprehensive assessment over the environmental impact and combustion efficiency of using ammonia/ hydrogen/diesel blends in a diesel engine

To reduce the dependence on traditional fossil fuels and promote low-carbon emissions, this article takes a four-cylinder four-stroke diesel engine as the research object and constructs a simulation model. It mainly simulates and studies the effects of different ammonia energy substitution rates (AESR) and hydrogen energy substitution rates (HESR) on the combustion and emission characteristics of diesel engines. Under the full load condition, the AESR was simulated within the range of 10 %–50 %. Subsequently, HESR of 0, 2 %, 4 %, 6 %, 8 % at AESR of 10 %, 20 %, 30 %, 40 %, and 50 % are set for further study. The research results indicate that with the increase of AESR, the combustion performance of the engine is improved. The emissions of NOx, CO2, and soot are reduced, but the emissions of unburned ammonia are significantly increased. Adding hydrogen to ammonia-diesel blended fuel can effectively reduce unburned ammonia emissions. Based on the comprehensive analysis results, it is more appropriate to choose a HESR of 4 % when the AESR is 10 %.

The effect of fusel oil and waste biodiesel fuel blends on a CI engine performance, emissions, and combustion characteristics

In this study, experimental engine tests were conducted to investigate the combustion, performance, and emission characteristics of a diesel engine using a fuel blend composed of diesel, biodiesel, and fusel oil. In the study, which was carried out by using fuels obtained from different wastes together in a diesel engine. Seven different fuels were prepared for experiments by adding waste cooking oil (30% and 50%) and fusel oil (5% and 10%) by volume to commercial diesel fuel. The tests were carried out on the Lombardini LDW 1003 engine, a three-cylinder diesel engine, at four different engine loads (10, 20, 30, and 40 Nm), and a constant speed (2000 rpm). The experimental results revealed that the use of WCO generally led to increased NOx emissions which generally decreased with the fusel oil addition to the fuel mixture. Considering diesel fuel as a reference at maximum load conditions, there was a 12.63% increase in NOx emissions with 50% WCO. A 2.45% decrease in NOx emissions was achieved by adding 10% fusel oil. Furthermore, HC emissions decreased with the addition of both fusel oil and WCO at all load levels. When diesel fuel is taken as a reference at maximum load conditions, a 90% reduction in HC emissions was achieved by adding 50% WCO, and a 50% reduction in HC emissions was achieved by adding 10% fusel oil. Additionally, when diesel fuel is taken as a reference at maximum load condition, it was observed that a 0.05% increase in the maximum cylinder pressure value with the addition of 50% WCO and a 2.09% increase in the maximum cylinder pressure value with the addition of 10% fusel oil.

Impact of multi-walled carbon nanotubes (MWCNTs) on hybrid biodiesel blends for cleaner combustion in CI engines

This study investigates the influence of multi-walled carbon nanotubes (MWCNTs) and hybrid biodiesel blends on the performance, combustion, and emission characteristics of a compression ignition engine. The hybrid biodiesel comprises waste frying oil methyl ester (WFOME), sesame oil methyl ester (SOME), and ultra-low sulfur diesel (ULSD) blended at 20 %:80 % by volume (B20). MWCNTs were added into B20 at 25 ppm and 50 ppm concentrations (B20-25MWCNT and B20-50MWCNT). Experimental analysis was conducted under varying engine loads and injection pressures, complemented by CFD simulations. Results demonstrate that the addition of MWCNTs significantly enhances B20 blend performance, with B20-50MWCNT exhibiting a 25 % increase in brake thermal efficiency and a 17 % reduction in brake specific fuel consumption compared to neat B20. Additionally, the incorporation of MWCNTs resulted in notable reductions in harmful emissions. NOx emissions for the B20 + 50MWCNT blend were reduced by up to 36 % compared to diesel and 43 % compared to B20. Smoke opacity and particulate emissions also showed significant decreases, highlighting the cleaner combustion facilitated by the presence of MWCNTs. The CFD simulations provided detailed insights into the combustion process, validating the experimental findings and elucidating the mechanisms behind the observed improvements. The enhanced fuel atomization, better fuel-air mixing, and catalytic properties of MWCNTs were identified as key factors contributing to the superior performance and reduced emissions.

Extraction and characterization of Cucumis melon seeds (Muskmelon seed oil) biodiesel and studying its blends impact on performance, combustion, and emission characteristics in an internal combustion engine

This study examines the performance, combustion, and emissions characteristics of a single-cylinder internal combustion diesel engine when fueled with a blend of diesel and biodiesel derived from muskmelon seeds. The kinematic viscosity of the extracted muskmelon seed oil was 6.1 cSt at 40 °C, which is higher than the kinematic viscosity of petroleum diesel of 2.6 cSt. Muskmelon biodiesel was further analyzed using thin-layer chromatography (TLC) and high-voltage separator tests. A comparison of the fuel properties of muskmelon biodiesel with conventional diesel fuel revealed that muskmelon biodiesel could be used alone or in a diesel–biodiesel blend to fuel compression diesel engines. In this study, muskmelon seed biodiesel was blended with diesel fuel at proportions of 10 %, 20 %, and 50 % (BD10, BD20, and BD50, respectively). At a relatively low rotational speed of 1200 rpm, the brake thermal efficiency (BTE) of the engine operated with BD10 and BD20 blends were 36.1 % and 36.0 %, respectively, while the brake-specific fuel consumption (BSFC) of the two blends were 0.260 kg/kWh, and 0.262 kg/kWh, respectively. These values closely resemble those typically observed in diesel fuel engines. Indeed, the average BTE of the BD20 blend was only 3.24 % less than the average BTE of diesel fuel. Diesel fuel generates less NOx and SO2 emissions compared to biodiesel blends: BD100 emitted the most NOx pollution of all fuels tested. In addition, BD10 released significantly more SO2 emissions compared to the other fuels tested. However, the BD20 blend outperformed all other blends in terms of CO, NOx, and SO2 emissions at high engine speeds. The only exception was H2S emissions, which were higher than BD50 and BD100. BD20 also exhibited significantly reduced CO emissions compared to diesel fuel, while BD10 emitted significantly more CO emissions than the other biodiesel blends. Our findings revealed that BD20 exhibited the best engine performance and lower emissions among all fuels tested. In other words, BD20 is the ideal fuel blend for use in diesel engines and does not require any alterations to the engine. Muskmelon waste seeds represent a non-edible waste stream that can be exploited in the production of biodiesel fuel, allowing for the upcycling of a potentially problematic thermochemical conversion feedstock. This potentially valuable use for waste muskmelon seeds in the energy sector could address the wastefulness associated with this particular waste stream.

An Adaptive Estimation Approach for Integrating Real-World Operation Dynamics in Engine-Out NOx Emission Modeling of a Wheel Loader

Accurately predicting engine-out nitrogen oxides (NOx) emissions on-board is crucial for effective emission control in heavy-duty engines. Real-world engine operating conditions, especially in non-road applications with frequent dynamic changes, can significantly affect NOx emission characteristics. However, these engine emission characteristics are conventionally measured on steady-state or regulated driving cycles, which may not fully reflect the emission levels under real-world operational dynamics. This highlights the necessity of integrating engine performance during transient operation into the NOx prediction model to enhance the accuracy of on-board predictions. This paper introduces a novel data-driven model to predict engine-out NOx emissions during the construction activities of a wheel loader. This paper begins by addressing discrepancies between steady-state map predictions and on-board NOx measurements. To bridge these gaps, the model identifies engine transient operating conditions by analyzing the time derivatives of engine speed and torque. The model structure integrates steady-state and transient emission maps, with the transient map being iteratively refined using the Kalman filter principle, thereby improving its accuracy and robustness in response to engine dynamics. The proposed method maintains a model structure that is easily implemented and similar to conventional steady-state emission maps, while also enabling online self-learning for model parameter updates. Model validation shows that the model has high prediction accuracy and the ability to differentiate between steady-state and transient engine working conditions during construction activities.

The influence of injection pressure and exhaust gas recirculation on a VCR engine fueled by microalgae biodiesel

AbstractBiodiesel has been chosen as a decent alternative to diesel in the context of establishing environmentally pleasant conditions and saving petroleum‐based resources for future generations. It is well‐established that biodiesel‐powered diesel engines may achieve outcomes equivalent to those of diesel engines. The current investigation was conducted to study the effect of injection pressure (190, 210, and 230 bar) and exhaust gas recirculation (EGR) (5%, 10%, and 15%) on a single‐cylinder variable compression ratio (VCR) diesel engine running using a B20 (20% MB + 80% PD) blend of microalgae biodiesel (MABD). This experiment was conducted in two stages. During the first stage of experimentation, the efficiency and emission characteristics of a diesel engine with a B20 blend of MABD at various fuel injection pressures and fresh air were investigated. During the second phase, fresh air was mixed with 5%, 10%, and 15% exhaust gases, and the experiment was conducted. It was discovered that increasing injection pressure to 230 bar provided considerable improvements. Brake thermal efficiency increased by 2.35%, brake‐specific fuel consumption decreased by 3.57% and pollutants such as carbon monoxide (CO), hydrocarbon, and smoke were reduced by more than 50% compared to conventional diesel. These reductions were similarly significant (over 22%) as compared to the B20 blend at lower injection pressure (210 bar). However, there was a slight trade‐off: nitrogen oxide (NOx) emissions increased partially (3.14%), while exhaust gas temperature (EGT) increased by 1.72% at a higher pressure. The study then investigated the influence of EGR (5%, 10%, and 15%) at various injection pressures. The optimal value seems to be 10% EGR at 230 bar injection pressure. This combination substantially reduced NOx emissions (by over 41% compared to the normal B20 blend) and EGT (by more than 8%), while having no notable effect on other performance or emission variables. Overall, the results show that employing a B20 MABD blend with high injection pressure (230 bar) and moderate EGR (10%) improves engine performance while reducing hazardous emissions.

Effect of excess air ratio and ignition timing on the combustion and emission characteristics of the ammonia-hydrogen Wankel rotary engine

As a hydrogen carrier, ammonia can suppress knock and enhance thermal efficiency of the hydrogen-fueled Wankel rotary engine (WRE), and achieve zero carbon emissions. This research established a three-dimensional fluid dynamics model coupled with detailed reaction kinetics of ammonia and hydrogen and verified it based on experiments. Incorporating 10% volume fraction of ammonia into the hydrogen-fueled WRE eliminates knock and decreases the excess air ratio (λ) from 1.8 to 1.4, effectively improving the indicated mean effective pressure (IMEP). The results indicate that when λ exceeds 1.4, flame propagation accelerates with higher concentration of the mixture. This enhances peak in-cylinder pressure and heat release rate, but it results higher NOx emissions. As λ varies from 1.8 to 1.4, NOx emission levels rise by 47.4%. At λ ≤ 1.2, the rapid flame propagation leads to short combustion duration, diminishing the power output. At this stage, the NO formation is dominated by H radicals, and the NOx production reaches its minimum value at λ of 1.0. In summary, the ammonia-hydrogen WRE achieves optimal performance at λ of 1.4 and ignition timing of −5 °CA after top dead center, the indicated thermal efficiency reaches 36.9% and the IMEP achieves 0.683 MPa.

Predicting combustion, performance, and emission characteristics of a compression ignition engine utilising coconut oil methyl ester and MoO3 nanoparticles

The present study used a blend of biofuel and nanoparticles to examine the effectiveness and emission properties of a four-stroke, single-cylinder, direct-injection diesel engine with an injection pressure of 250 bar. The use of MoO3 in biodiesel enhances its environmental sustainability and dependability, making it a promising substitute for traditional diesel fuel. The study emphasises the ecological advantages of using a combination of coconut oil and MoO3 to accomplish the production of renewable energy. MoO3 nanoparticles ultimately function as an oxidation catalyst, enhancing combustion. A study with MoO3 nanoparticles at 50 and 100 ppm concentrations was carried out. Utilising a photo spectrometer, stability was determined. The CI engine demonstrated improved thermal efficiency and reduced Fuel Consumption compared to diesel, both at full load conditions and at 64.5 bar pressure. The performance, combustion, and emission parameters were precisely forecasted using Design Expert, exhibiting a robust connection with the testing results. The Rb values for Brake Specific Fuel Consumption (BSFC), Brake Thermal Efficiency (BTE), Peak Cylinder Pressure (P-CA), Net Heat Release Rate (NHRR), Crankcase Heat Release Rate (CHRR), Carbon Monoxide (CO), Unburned Hydrocarbons (UHC), Nitrogen Oxides (NOX), and Smoke Opacity are 0.997, 0.9998, 0.8898, 0.979, 0.9838, 0.9815, 0.9917, 0.9958, and 0.9261 respectively.

Prediction of the Performance and emission characteristics of diesel engine using diphenylamine Antioxidant and ceria nanoparticle additives with biodiesel based on machine learning

This study explores the impact of incorporating antioxidants diphenylamine (DPA) and nanoparticle ceria (CeO2) into Jatropha biodiesel (B30) blend on engine performance and exhaust emissions. The fuel blends utilized in this study consists of diesel, B30, B30 with 100 ppm of antioxidant diphenylamine (B30+DPA100), and B30 with 50 ppm of antioxidant diphenylamine and 50 ppm of nanoparticle ceria (B30+DPA50+CeO250). The experiments were designed using the design of experiment methodology, and they were conducted using various fuels to assess both engine performance and exhaust emissions characteristics. Further, machine learning algorithms (multilayer perceptron, random forest regression, and K-nearest neighbors) has been employed to develop a model for accurately predicting experimental outcomes. The K-nearest neighbors model surpassed the multilayer perceptron and random forest regression models, demonstrating a higher coefficient of determination value and precise outcome predictions. The experimental results reveal that adding antioxidants diphenylamine and nanoparticles ceria at 50 ppm to B30 significantly reduced nitrogen oxides emissions. Compared to B30, B30+DPA50+CeO250 showed a 6.35 % decrease in brake specific fuel consumption and an 8.68 % reduction in nitrogen oxides emissions. However, there was a slight increase of 5.74 % in brake thermal efficiency. Additionally, B30+DPA50+CeO250 exhibited a 2.54 % reduction in maximum cylinder pressure compared to B30.

Experimental investigation of engine performance and emissions, and characterization, of waste transformer oils and diesel blends with biodiesel produced from olive oil wastes in a CI engine

In this study, five different fuel blends were prepared by mixing biodiesel obtained from olive oil wastes using transesterification method, waste transformer oil, and Euro diesel in different ratios. The important physicochemical properties of the prepared fuel blends and produced biodiesel were determined by gas chromatography, Fourier transform infrared spectroscopy, and thermogravimetric analysis/differential scanning calorimetry analyses, and their characterizations were carried out. Then, the effects of the prepared fuel blends on engine performance and emission characteristics were investigated in a compression ignition engine. The experiments were performed with five different fuel blends (TD30, TD30B10, TD30B20, TD30B30, and D100) at 1000, 1500, 2000, and 2500 rpm. At all speeds, each fuel blend produced an average torque value that was highest for D100 fuel and lowest for TD30 fuel The average BP value produced by each fuel at all engine speeds was highest in D100 fuel and lowest in TD30 fuel. The results of the experiments showed that there was a 23.98% decrease in the average NOx emissions of TD30 fuel blend compared to the average NOx emissions of D100 fuel at all engine speeds. It was observed that all important fuel properties such as density, kinematic viscosity, and pour and cloud points of all fuel blends met the fuel standards.

Role of hydrogen-enrichment for in-direct diesel engine behaviours fuelled with the diesel-waste biodiesel blends

Carbon footprint indicates the total amount of greenhouse gases released into the atmosphere by individuals, institutions and countries. The widespread use of fossil fuels is a big player which increases the carbon footprint. Therefore, switching to sustainable alternatives in energy production and consumption is an effective step in combating climate change, as well as efforts to prevent the depletion of fossil fuels. In this regard, although biodiesels offer a solution to the depletion of fossil fuels, with this advantage, the effects of production processes and use on environmental sustainability should be taken into consideration. Many scientific studies have shown that engine performance remains below standards with biodiesel. The availability of hydrogen as an energy carrier in cylinder to overcome the above-mentioned negative situations has recently become a popular topic for fuel researchers. In this work, the diesel-biodiesel fuels were blended proportionally and tested on a three-cylinder water-cooled in-direct diesel engine at varying loads (15, 30, 45, and 60 Nm) and a constant engine speed of 2200 rpm for observing the effects of test fuels on combustion, performance, and emissions characteristics of diesel engine. First of all, conventional diesel fuel (D) was used to obtain reference data, and then B20 fuel obtained by mixing waste cooking oil with 20 % by volume of diesel fuel was used. The remaining 4 fuels are test fuels obtained by giving hydrogen from the intake manifold at different flow rates (10, 20, 30, and 40 L/min) in addition to B20 fuel. These fuels are called B20 + 10 Lpm H2, B20 + 20 Lpm H2, B20 + 30 Lpm H2 and B20 + 40 Lpm H2, respectively. As a result, the BSFC of B20 fuel increased by 8.78 % compared to diesel fuel, and then the addition of hydrogen dropped the BSFC value by 8.8 %, 13.02 %, 17.16 %, and 22.12 % for B20 + 10 Lpm H2, B20 + 20 Lpm H2, B20 + 30 Lpm H2, and B20 + 40 Lpm H2, respectively. Hydrogen enrichment also had a positive impact on BTE. Although the BTE dropped by 6.14 % in B20 fuel compared to diesel, it increased by 4.51 %, 5.05 %, 5.62 %, and 7.12 % in B20 + 10 Lpm H2, B20 + 20 Lpm H2, B20 + 30 Lpm H2 and B20 + 40 Lpm H2 fuels, respectively. The addition of 10, 20, 30, and 40 Lpm H2 to B20 fuel reduced NOx emissions by 31.25 %, 33.08 %, 38.87 %, and 41.46 %, respectively, and also reduced CO emissions by 17.47 %, 30.73 %, 51.8 % and 59.04 % respectively.

Using CRITIC-TOPSIS and python to examine the effect of 1-Hepatnol on the performance and emission characteristics of CRDI CI engine with split injection

Recently, biofuels with higher alcohol content have become a promising alternative to diesel fuel. These fuels are appealing because they are sustainable, renewable, and possess attractive fuel properties. This study uses a split injection strategy to analyze the performance and emissions of a CRDI diesel engine fueled by 1-heptanol. The work involved testing different fuel blends, ranging from 10 % to 30 %, while maintaining a constant engine speed of 1500 rpm and varying the operating load between 0 kg and 12 kg in 4 kg increments. During the second stage, the CRITIC-TOPSIS method determines the objective weights and rankings of various criteria and alternatives. A Python approach based on machine learning was used to ensure the CRITIC-TOPSIS results were accurate. Seven criteria were evaluated to maximize BTE while minimizing BSFC, NOx, smoke opacity, HC, CO, and CO2. The experimental results showed a slight drop of 2.98 % in BTE and an increase of about 13.33 % in BSFC. NOx and smoke opacity were reduced by 7.13%–4.53 %, while there was a 12.12 % increase in HC, 6.45 % higher CO, and a 5.5 % increase in CO2 at full load. Adding 1-heptanol to diesel and using a split injection strategy significantly reduced NOx and smoke opacity. The final ranking and best blend are determined using CRITIC-TOPSIS and Python algorithms to estimate performance and emissions criteria. At a load of 4 kg, D100 ranks first with a relative closeness value of 0.642, while at a pack of 8 kg, the blend HP20D80 ranks first with a relative closeness value of 0.633. According to the rankings, the HP20D80 blend is the best option for achieving optimal performance and reduced emissions in CRDI diesel engines. A research paper has presented a unique approach to multiple criteria decision-making (MCDM) validated using a Python algorithm. This method can assist decision-makers in making better-informed choices when faced with MCDM problems that involve various criteria and alternatives.

Influence of Hydrogen induction on performance and emission characteristics of an agricultural diesel engine fuelled with cultured Scenedesmus obliquus from industrial waste

The use of microalgae in waste water treatment has been recognised as crucial for managing and treating effluent from industrial sources. Present study used Scenedesmus obliquus (SO) strains in industrial waste cultured medium, grown algae were collected and dried, further with dried mass to algae bio fuel by transesterification process. Four fuel blends were created by adjusting the SO concentration from 10% to 40% by volume. Then SO blend was examined with impact of hydrogen induction on compression ignition engine. The addition of H2 to SO biodiesel enhances its net calorific value because of its high calorific content.Adding H2-inducted SO proportion to diesel reduces HC, NOx, and CO levels, with a negligible performance dip. At full loads, SO40 showed a significant improvement in emission levels, with a 19.81% reduction in NOx, a 51 ppm drop in HC and 1.146% dropobserved in CO compared to diesel. For the SO10 mix, BTE and BSEC were found to be 2.86% and 2103.77 kJ/kW-hr, respectively, superior to other SO blends. Subsequently, it is of crucial significance to acknowledge the significance of the potential those microalgaeprovides for the production of sustainable energy through the reprocessing of industrial effluents.

A comparative investigation of the operating performance and emission characteristics of various diesel engines driving the firefighting pump

The investigation of engines with different performances driving the same load-consuming device is necessary for practical applications. In this paper, three diesel engines with varying capacities for driving the same firefighting pump for high-rise residential buildings were studied and compared for their performance, combustion parameters, and emissions by the simulation method. The AVL BOOST software is utilized to establish theoretical combustion models for these engines. The operating balance point of each engine is determined, and the appropriate transmission ratio of the drive train system is proposed to be applied. The results show that the working partial load modes of Model 1 at 91 % engine load and 2970 rpm, Model 2 at 74 % engine load and 2960 rpm, and Model 3 at 57 % engine load and 2490 rpm. The engine works in its higher load mode, producing higher brake specific fuel consumption (BSFC), higher NOx and CO emissions, lower soot formation, and vice versa. The engine operates at its lower load, resulting in decreased BSFC, less NOx and CO emissions, and more soot generation. The results suggest that Model 2 in the present work is the option that can balance the factors of engine power, initial investment cost, fuel consumption economics, and emissions. The findings obtained from this work are the scientific foundations to support the design of the firefighting pump systems when considering comprehensive factors of technical technology, investment cost, and environmental consideration.

Effect of n‐pentanol with novel water hyacinth biodiesel‐diesel ternary blends on diesel engine performance and emission characteristics

AbstractPresent research deals with crude oil production from water hyacinth biomass and its biodiesel preparation. Alcohol additive n‐pentanol is mixed with biodiesel and diesel blends to identify their effects on diesel engine performance and emission parameters experimentally. Water hyacinth oil (WHO) is produced through Soxhlet extraction technique, and its biodiesel is prepared by transesterification. n‐pentanol is mixed through magnetic stirring in biodiesel‐diesel blends to improve their combustion quality and efficiency. Prepared fuel blends properties are examined as per ASTM standards. Experimental results reveal that, BSFC and BTE are evaluated as 0.26 kg/kW‐h and 29.5%, respectively, with HC emissions as 29 ppm, CO emissions as 0.28 vol%, NOx emissions as 330 ppm and CO2 emissions as 2.21 vol% for WHB20D75P5 fuel at maximum load. The comparison of D100 and WHB20D80 with respect to WHB20D75P5 reveals 3.27% reduction and 7.27% improvement in BTE, respectively. Both HC and CO are reduced by 14.70% and 22.22% for WHB20D75P5 fuel compared to diesel. NOx and CO2 emissions are increased by 6.79% and 12.75% for WHB20D75P5 fuel compared to diesel. Overall, WHB20D75P5 fuel is the best performer.

Enhancement of combustion, performance and emission characteristics of diesel engines fuelled with jatropha-karanja biodiesel using EGM and TGME as additive

The oxygenated additives can improve the physical properties of biodiesel blends to achieve enhanced characteristics of a diesel engine. The present work has investigated ethylene glycol monoacetate (EGM) and tri-ethylene glycol mono-methyl ether (TGME) as potential additives for the jatropha-karanja dual blended biodiesel for improved characteristics of diesel engines. The experiments have been conducted with a single cylinder four stroke diesel engine operating at constant speed of 1500 rpm. The performance, emission and combustion parameters of the engine were investigated with pure diesel, jatropha-karanja dual blended biodiesel having 20 % of methyl ester and the biodiesel added with 2, 4, and 6 % of both the additives respectively. The doping of additives improved the brake thermal efficiency by 4.1 and 4.7 % with brake specific fuel consumption dropped by 0.18 and 0.2 kg/kWh. The additives reduced the hydrocarbon emission by 29.8 % and carbon monoxide by 40 % with a slight increase in NOx emission by 5.2 %. The cylinder pressure attained value near to pure diesel while the heat release rate increased by 12.6 % indicating proper fuel combustion inside the engine cylinder. Thus, the oxygenated additives can suitably be adopted as performance improvers in biodiesel fuels for automotive engines.

Comprehensive Review on Technical Developments of Methanol-Fuel-Based Spark Ignition Engines to Improve the Performance, Combustion, and Emissions

Abstract Methanol (CH3OH) is emerging as a viable alternative to fossil-based fuels, addressing the increasing global energy demand while promoting sustainability. The spark ignition (SI) engines are widely used to run the automobile sector. Methanol as a widely available and cheap source of energy can be strongly replaced with expensive and limited fossil-based fuels to power the SI engines. The prime objective of this study is to evaluate the advancements made in improving the fuel blends, performance, combustion, and emission characteristics of methanol-fueled SI engines. The investigation commences by examining the various technical improvements implemented in methanol-fueled SI engines to optimize their overall performance. These developments include advancements in fuel blends, engine design, combustion strategies, fuel injection systems, ignition systems, engine load, etc. The impacts of these developments on the performance parameters including brake thermal efficiency, power output, torque, fuel efficiency, thermal efficiency, etc., combustion parameters including ignition delay, combustion duration, heat release rate, in-cylinder pressure and temperature, etc., emission parameters including hydrocarbon, carbon monoxide, nitrogen oxide, formaldehyde, unburned methanol, etc., is reviewed comprehensively. The effectiveness of emission control techniques and the potential for meeting stringent environmental regulations are explored. The review paper then considers the wider implications of methanol-fueled SI engines by examining their technical, environmental, economic, and renewable applications. The technical aspects cover the compatibility of methanol-fueled SI engines with existing infrastructure and the associated challenges and opportunities. The environmental considerations delve into the potential reduction of greenhouse gas emissions and the overall sustainability of methanol as a renewable fuel. Finally, the research direction of methanol SI engines is discussed, highlighting the emerging trends and prospects in this field. The review paper concludes with recommendations for further research and development, addressing the key areas that require attention to unlock the full potential of methanol as an efficient and sustainable fuel for SI engines.

Waste to fuel: A detailed combustion, performance, and emission characteristics of a CI engine fuelled with sustainable fish waste management augmentation with alcohols and nanoparticles

All over the world, 130 million tonnes of fish waste have been generated per annum. Improper disposal of such waste leads to environmental pollution, habitat degradation, oxygen depletion, spread of pathogens, parasites, and diseases. From this point of view, this research motivated to benefit from such fish waste by converting an alternative fuel along with various additives for diesel engines. Fish wastes gathered from the fish market are used as feedstock for producing fish waste biodiesel (FWBD) through the transesterification process. The derived fish waste biodiesel (FWBD) 60 %, 20 % diesel, and 20 % n-butanol (C4H9OH) by volume were blended (60FWBD+20Bu+20D) to form the test fuels. Then the fuel blends were used to convert two nano fuels by separately adding zinc oxide and graphene nanoparticles of 100 ppm along with sodium dodecyl sulphate surfactant, and the nanoparticles-added test fuels were exposed to sound waves of 50 kHz in an ultrasonicator for 1 h. These fuels were characterized to derive and ensure the fuel properties for diesel engines and tested such fuels in a 5.2 kW CI engine to do a comparative study. The experiments were conducted at the constant engine speed of 1500 rpm, and varying engine loads from 25 % to 100 % with intervals of 25 %. When the fish waste biodiesel was added to diesel fuel, the engine performance worsened in a given engine load, but it started to improve with the existence of nanoparticles. Compared to 60FWBD+20Bu+20D, graphene-based nano fuel blend recorded 1.99 % higher BTE, but 15.03 % higher NOx. Similarly, compared to 60FWBD+20Bu+20D, zinc oxide-based nano fuel blends recorded 6.75 % higher BTE and reduced NOx, CO, HC, and smoke emissions by 29.97 %, 15.98 %, 22.0 %, and 16.03 % respectively. In conclusion, the present research reveals that fish wastes can be used in diesel engines without any modification on the vehicular system, and this may contribute to both slowing down the rate of depletion of fossil reserves and the waste management of the fish wastes from nature in a useful way.

Effect of exhaust gas recirculation on the performance and emission characteristics of diesel engine with hydrogen fuel and nano additives

One of the most popular techniques for reducing emissions, in particular nitrogen oxide (NOX), carbon monoxide (CO), carbon dioxide (CO2), and particulate matter (PM), is exhaust gas recirculation (EGR). In an EGR system, the intake manifold is used to re-introduce some of the exhaust gases into the combustion chamber. Diesel engine performance could be enhanced by employing the right number of nano additives. Nano additions aid in increasing efficiency when using hydro fuel. The following systems are impacted by the use of EGR: brake specific fuel consumption (BSFC), diesel engine combustion characteristics, brake thermal efficiency (BTE), engine speed, CO2 and HC emissions, turbocharged diesel engine performance characteristics, fuels, temperature, and on EGR.