Engine performance parameters, including fuel conversion efficiency (FCE), power, torque and specific fuel consumption (SFC), can be affected by variables such as ignition timing (IGT), injection ...timing (IT) and hydrogen volume fraction (H2%). In this paper an engine fueled with different H2/CNG blend rations from 0 to 50% volume under ignition and injection timing at different speeds were investigated. For model validation, the engine operating conditions were simulated using the AVL fire software and compared with experimental results. The statistical comparison showed that there was no significant difference between them. Also, a support vector machine (SVM) was used to study the engine's behavior according to the variables studied. The SVM model predicted the FCE, power, torque, SFC and CO with error of less than 4%. The Genetic Algorithm (GA) was used to find optimal IGT, IT and H2% values to achieve optimum engine performance. Therefore, the results showed that the optimum engine operating conditions depend on the engine speed. Also, the results showed that independent variables (IT, IGT and H2%) maximize the engine performance and minimize SFC and CO emission. So that the optimum use of hydrogen in this research at different engine speeds was between 20% and 30%.
•Effect of hydrogen fuel in direct injection engine was studied.•Use of HCNG fuel can improve engine performance and exhaust emissions.•The SVM model could predict the engine performance and CO with error of less than 4%.•Ignition timing, injection timing and hydrogen volume fraction at different engine speeds.
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•Dual-fuel PCCI mode reduced NOx and smoke emissions significantly.•Effects of n-pentanol addition on PCCI engine powered by tire oil were explored.•n-pentanol prolonged the ...autoignition period and increased combustion duration.•Adding CZ nanoparticles improved thermal efficiency and reduced HC/CO emissions.
The main aim of this study was to investigate the effect of n-pentanol percentage on the performance, combustion, and emission characteristics of a premixed charge compression ignition (PCCI) engine operated on dual-fuel mode. The primary fuel used in the engine was a blend of diesel fuel and pyrolytic oil, which was obtained from waste tires by the pyrolysis process. Moreover, CuO/ZnO (CZ) nanoparticles were added to the fuel blend to supply excessive oxygen for better combustion. In addition, n-pentanol is an ecologically innovative and cost-competitive compound used as a secondary fuel with high octane rating. For this experimental work, the fuel blend was prepared by adding 20% waste tire pyrolysis oil to 80% diesel fuel containing 50 ppm CZ nanoparticles, while n-pentanol was sprayed into the intake manifold with varying percentages, namely 10%, 20%, and 30%. As a result of the PCCI dual-fuel mode, PTO20CuZnO50P10 was found to be the best selection since it brought a significant decrement in emission parameters such as oxides of nitrogen (NOx), carbon monoxide (CO), hydrocarbon (HC), and smoke was 12%, 37%, 10%, and 23%, respectively, compared to the conventional diesel engine at peak load condition. However, it is recorded a reduction in brake thermal efficiency and an increase in specific fuel consumption under PCCI mode using PTO20CuZnO50P10 compared to the conventional diesel engine. In general, PTO20CuZnO50P10 was chosen as the best fuel for the PCCI mode of operation aiming to reduce pollutant emissions.
Transportation and shipping activities are major contributor to air pollution at sea where most of it occurs as a result of exhaust emissions from ships. Stringent emission limitations enforced by ...the International Maritime Organization have hastened the need to find a new alternative fuel for marine diesel engines. Thus, biodiesel fuel was chosen as one of the environmentally friendly alternative energy that can reduce ship toxic gas emissions and at the same time reduces dependence on petroleum-based fuels. Therefore, the purpose of this paper is to provide a comprehensive review of biodiesel as an alternative fuel for marine diesel engine applications. This review covers the biodiesel fuel background, engine performance, history, recent progress, engine warranty, issues, challenges, and possible solutions on using biodiesel for marine applications. A significant number of literatures from indexed journals were cited accordingly. The results of previous studies had shown that the use of biodiesel would mostly increase the amount of brake specific fuel consumption and nitrogen oxide gas while conversely reducing other toxic gas emissions. Although a number of issues and challenges arise, most marine engine manufacturers give conditional warranty against the use of biodiesel in the engines. The study concluded that biodiesel and its blends have a bright future in the marine sector, provided some of the highlighted issues can be solved.
•Stringent emission control triggered a new alternative fuel for marine engines.•Biodiesel fuel offer more environmental friendly and alternative energy.•This review covers biodiesel background, marine engine, history and recent progress.•Most marine engine manufacturers give conditional warranty for biodiesel used.•The study shows that biodiesel and its blend has a bright future in marine sector.
To accelerate the energy transition, starting February 1, 2023, the Indonesian government has made it mandatory to use biodiesel (B35). Biodiesel differs from diesel oil, especially its greater ...viscosity and density, lower heating value, and high NOx emission. Therefore, this research has been carried out by adding the additive diethyl ether (DEE) to B35 to reduce the viscosity and density, increase the cetane number, and reduce emissions. The effects of diethyl ether on engine performances have been evaluated, including parameters of torque, power, brake thermal efficiency, brake-specific fuel consumption, exhaust emissions, and lubricants. The fuels used are B35 (35% FAME palm oil + 65% diesel oil), and B35 + DEE, with a DEE volume percentage of 3% to 6%. Diesel fuel (B0) was used as a comparison. Tests were carried out in the engine performance test laboratory using the heavy-duty diesel engine Komatsu SAA12V140E-3 at various engine speeds. The test results showed that adding diethyl ether slightly increases the average maximum power, increases brake thermal efficiency, and reduces brake-specific fuel consumption and emissions compared to B35. Very significant effects were seen in NOx and SO2 exhaust emissions. At maximum load, the mixture with 4% diethyl ether gave the greatest brake thermal efficiency, the lowest brake-specific fuel consumption, and the greatest reduction in NOx and SO2 emissions, respectively 7.69%, 6.30%, 53.48%, and 40.89% compared to B35, and 2.24%, (-0.90%), 48.88% and 71.17% compared to B0, respectively. Evaluation of lubricating oil during the performance test did not show a significant difference for all types of fuel used.
In recent years renewable and cleaner fuel for diesel engines are compulsory due to depletion of fossil fuel. Various types of bio-based fuels are investigated by the researchers. Biodiesel is ...anticipated as potential contenders of diesel fuel. Though it is possible to utilize pure biodiesel in diesel engines, some burdens like higher density, lower cetane number and lesser calorific value hinder it from replacing conventional diesel completely. Therefore, using blends with biofuels in diesel engines has a preference. Thus, this paper reviews two different approaches on the role of nanoparticles on biofuel production and effects of nanoparticles in biodiesel–diesel fuel blends on performance, combustion analysis and emission characteristics of diesel engines. Wide range of results from previous research studies with potential and application of nanoparticles in bioethanol production, the effect of the addition of nanoparticles into diesel fuel with different biofuels ratios are collected in this review study. There are different engine performances enhancing methods surveyed. Nanoparticles can be utilized in the production of biofuels from feedstock pre-treatment to chemical reaction as catalysts. It was observed from the overall results that by adding nanoparticles, there was a significant reduction in the brake specific fuel consumption about 20% to 23% as compared with biodiesel–diesel blends with and without alcohol as additives. Besides as nanoparticles possess high thermal conductivity, the addition of nanoparticles enhanced the process of combustion and increases the brake power about 2.5% to 4%. Emission results showed that in most reviews, NOx emission is increased by up to 55%, while HC, CO and PM are decreased significantly. It was concluded from the study that a diesel engine could be effectively run and give better performance and effective regulated emissions on the application of added nanoparticles with biodiesel and their blends as fuel in a CI engine.
•Most of the fuel properties can be enhanced by adding nanoparticles.•NPs in biofuel production provides steady chemical reaction and reduces biofuel’s cost of production.•Use of NPs significantly increases BTE and reduces BSFC in diesel engines.•NPs reduces harmful exhaust emission discharged from diesel engine.
The purpose of this study is to experimentally analyse the performance and the pollutant emissions of a four-stroke SI engine operating on ethanol–gasoline blends of 0%, 5%, 10%, 15% and 20% with the ...aid of artificial neural network (ANN). The properties of bioethanol were measured based on American Society for Testing and Materials (ASTM) standards. The experimental results revealed that using ethanol–gasoline blended fuels increased the power and torque output of the engine marginally. For ethanol blends it was found that the brake specific fuel consumption (bsfc) was decreased while the brake thermal efficiency (
η
b.th.) and the volumetric efficiency (
η
v
) were increased. The concentration of CO and HC emissions in the exhaust pipe were measured and found to be decreased when ethanol blends were introduced. This was due to the high oxygen percentage in the ethanol. In contrast, the concentration of CO
2 and NO
x
was found to be increased when ethanol is introduced. An ANN model was developed to predict a correlation between brake power, torque, brake specific fuel consumption, brake thermal efficiency, volumetric efficiency and emission components using different gasoline–ethanol blends and speeds as inputs data. About 70% of the total experimental data were used for training purposes, while the 30% were used for testing. A standard Back-Propagation algorithm for the engine was used in this model. A multi layer perception network (MLP) was used for nonlinear mapping between the input and the output parameters. It was observed that the ANN model can predict engine performance and exhaust emissions with correlation coefficient (
R) in the range of 0.97–1. Mean relative errors (MRE) values were in the range of 0.46–5.57%, while root mean square errors (RMSE) were found to be very low. This study demonstrates that ANN approach can be used to accurately predict the SI engine performance and emissions.
In this study, we studied the hydrocracking of waste chicken oil (WCO) catalyzed by mesoporous SO42−/KIT-6. The study included WCO extraction, SO42−/KIT-6 catalyst synthesis, hydrocracking, and ...catalytic characterization. XRD patterns revealed intense peaks in the low-angle region, with shoulder peaks showing an increase in sulphate loading from 10% to 30%. The BET-specific surface area for the pure KIT-6 supports measured at 1003 m2/g, indicative of a well-defined mesoporous structure. Thermogravimetric analysis (TGA) showed a two-stage weight loss, attributed to the elimination of hydrated water (about 200 °C) and decomposition of sulphate ions (400–450 °C). SEM analysis highlighted the surface morphology of the active SK-2 catalyst. Hydrocatalytic and catalytic cracking reactions were performed, and about 99.8% conversion was achieved with 20 mL/H H2 flow, whereas higher production of bioliquids was observed at a flow of 15 mL/h. The hydrocracking mechanism was also studied to understand the formation of lower hydrocarbons. GC analyses of simulated distilled gasoline, kerosene, and diesel showed diverse hydrocarbon compositions. For engine testing, non-hydrocracked fuel rose to 28 kW at 3000 rpm and declined to 21 kW at 3500 rpm. Emission analysis revealed decreasing trends in NOX emissions of hydrogen-rich blends, with values of 65 ppm, 54 ppm, and 48 ppm for petrol, NHBL, and HBL, respectively. Similarly, SO2 emissions reduced from petrol to NHBL and HBL at 910 ppm, 800 ppm, and 600 ppm, respectively, suggesting reduced environmental impact. CO emissions exhibited a substantial reduction in NHBL (0.90%) and HBL (0.54%) compared to petrol (2.70%), emphasizing the cleaner combustion characteristics. Our results provide a comprehensive exploration of waste chicken oil hydrocracking, emphasizing catalyst synthesis, fuel characterization, engine performance, and environmental impact, thereby contributing valuable insights to the field of sustainable bioenergy.
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•Comparison between hydrocracking and catalytic cracking is presented.•Chicken waste oil was converted into maximum biodiesel range of hydrocarbons.•SO42−/KIT-6 material performed better than KIT-6 material in biodiesel conversion.•15 mL/h of H2 flow produced 80.3 % of bio liquid yield.•Hydrocracked diesel's maximum BSFC at higher rpm shows fuel's efficiency.
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•Different power output modes correspond to different durations of each stroke.•Engine performance under power output by Shaft 3 is superior than Shaft 1.•The charging efficiency at ...3000r/min is 95.36% under power output by Shaft 3.•Maximum power output is 40.9 kW corresponding to the thermal efficiency of 38.08 %.
As a new type of internal combustion engine, opposed rotary piston (ORP) engine has the advantages of simple structure and high working frequency, and can achieve high power density. Consequently, it stands as an ideal power source for hybrid power systems and unmanned aerial vehicles. The ORP engine has different power output modes, corresponding to different piston rotation and volume evolutions of combustion chamber. However, the effect of power output modes on kinetics characteristics and in-cylinder combustion of ORP engines are still uncovered. In this paper, the kinematic model of an ORP engine is established for scenarios involving power output by different shafts (Shaft 1 and Shaft 3). Meanwhile, the piston rotation patterns and cylinder volume variations are investigated correspondingly. Further, three-dimensional numerical model of the ORP engine is established, enabling analysis of in-cylinder combustion characteristics, engine performance, as well as nitrogen oxides (NOx) emissions. The results indicate that the volume variations of all cylinders follow a consistent pattern under the power output by Shaft 3. A pair of opposed cylinders features longer durations of intake and expansion strokes, and shorter durations of compression and exhaust strokes, the other pair of combustion chambers is the opposite under the power output by Shaft 1. The engine demonstrates a charging efficiency of 95.36 %, with corresponding indicated thermal efficiency and indicated power output of 38.08 % and 40.9 kW, respectively. The two adjacent cylinders present significantly different operation processes in the case of the power output by Shaft 1, achieving charging efficiencies of 94.29 % and 89.11 %, respectively, with the indicated thermal efficiency of 34.49 % and 31.60 %. The corresponding minimum indicated specific fuel consumption under the two power output modes are 211.7 g/kW∙h and 243.7 g/kW∙h, respectively, accompanied by NOx emission factors of 25.3 g/kW∙h and 17.6 g/kW∙h. With the given range of ignition timing, a trade-off relationship exists between the engine performance and NOx emissions. The power density of the case of power output by Shaft 3 is superior to that of Shaft 1.
•Influence of Jatropha biodiesel blended with nano additives on diesel engine performance.•Present work considers nano additives such as CNTs, TiO2 and Al2O3 for analysis.•J20Al100 at 75% of engine ...load produced a higher decrease in exhaust gas temperature.•J20C100 has a maximum decrease in smoke emission (up to 50% at 75% of engine load).•J20C50 has maximum decrease in NOx emission (up to 52% at 75% of engine load).
Increasing energy demands coupled with the depletion of fossil fuel and increased rate of fuel consumption along with the production of harmful emissions led to the intensive research on alternative fuels. Biodiesel was derived from Jatropha oil by acid esterification, followed by a trans-esterification process. Jatropha biodiesel blend of 20% volume percentage was prepared by mixing diesel and biodiesel oils. Nano additives such as CNTs, TiO2, and Al2O3 are used for enhancing the fuel characteristics. These additives were blended with biodiesel blend at the rate of 25, 50, and 100 ppm, respectively. This paper aims to evaluate the performance and exhaust emissions of a diesel engine utilizing Jatropha biodiesel blend by including the nano additives. An experimental test rig was mounted on a single-cylinder diesel engine to measure performance and emissions at various engine loads. Tests showed that, biodiesel blend with nano Al2O3 as J20Al100 led to a maximum improvement of 6.5% in thermal efficiency compared with all other fuels experimented. Jatropha biodiesel blend with CNTs as J20C50 produced higher decreases in CO and NOx emissions by about 35 and 52%, respectively compared with all fuels. Jatropha biodiesel blend with TiO2 as J20T25 produced higher reductions in HC and smoke emissions by about 22 and 50%, respectively compared with all other fuels. Jatropha biodiesel mixed with nano particles (denoted as J20Al100, J20T25 and J20C50) achieved improvement in engine performance and emissions reductions compared with the other tested fuels.
•Novel study of behavior of nano additives at various injection strategies.•At advanced injection timing, ignition delay and CO2 reduces and there is an increase in combustion duration, HC, CO and ...NOx emissions.•At retarded injection timing, cylinder pressure and heat release occurs away from TDC.•Reductions in emissions of HC, CO, NOx and smoke were observed.•Nanoparticle combustion was effective in retarded injection timing as it reduces almost all the harmful pollutants.
The current experimental work focusses on influence of Alumina (Al2O3) nanoparticle on various injection strategies. Experiments were conducted with three different injection timings (IT) namely, original timing (ORG IT) of 23deg bTDC, advanced timing (ADV IT) of 27deg bTDC and retarded timing (RET IT) of 19deg bTDC. The base fuel used is a blend of biodiesel (20%), diesel (70%), and ethanol (10%) (known as BDE). Alumina nanoparticles were synthesized, characterized by SEM and XRD analysis and blended with BDE blend at a fraction of 25ppm using ultrasonicator. The effect of 25ppm Al2O3 in BDE blend at ORG IT, ADV IT and RET IT were experimented in a single cylinder diesel engine and the following results were obtained. Al2O3 addition at ADV IT resulted in higher peak pressure and heat release rate occurring nearer to TDC, higher hydrocarbon (HC), higher carbon monoxide (CO), lower carbon dioxide (CO2), higher nitrogen oxides (NOx), higher exhaust gas oxygen (EGO), higher combustion duration (CD) and lower ignition delay (ID). Whereas, Al2O3 addition in RET IT causes lower cylinder pressure and heat release away from TDC, followed by simultaneous reductions of HC, CO, NOx and smoke opacity. In addition, higher levels of EGO and ID along with lowered brake specific fuel consumption (BSFC) and CD were observed with Al2O3 addition in RET IT. Overall, the influence of 25ppm Al2O3 in RET IT of 19deg bTDC resulted in better engine performance, combustion and emission characteristics.
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