An Influence of antioxidants and nanoparticles with Ceiba pentandra biodiesel/diesel blends on performance and emission characteristics of diesel engine

This investigation examined the effect of incorporating cerium oxide (CeO2) nanoparticle into diesel and waste plastic oil (WPO) blends on the combustion, performance and emission characteristics of the diesel engine. The WPO was extracted from low density polyethylene using plastic pyrolysis. The blending of diesel and WPO with combination of D70:WPO30 and D50:WPO50 was prepared to evaluate the engine operation. Additionally, the spherical sized CeO2 with 50 mg l−1 and 100 mg l−1 was added with this blend. The various blends named as Diesel, D-WPO30, D-WPO30+Ce50, D-WPO30+Ce100, D-WPO50, D-WPO50+Ce50 and D-WPO50+Ce100 were used in this investigation to operate the engine under various load conditions. The experiment was performed using water cooled common rail direct injection (CRDI) diesel engine with prepared D-WPO blend. Different characteristics such as In-cylinder pressure (CP), heat release rate (HRR), ignition delay time (IDT), brake thermal efficiency (BTE), brake specific fuel consumption (BSFC) and exhaust gas temperature (EGT), carbon monoxide (CO), hydrocarbon (HC), nitrogen oxide (NOx) and smoke opacity emission are studied with respect to the effect of different blends and applied load used. It was observed that increasing of CeO2 nanoparticles in blend improved the overall performance and emission of the engine. Form the results, D-WPO30+Ce100 blend showed enhanced brake thermal efficiency (BTE), brake specific fuel consumption (BSFC) and exhaust has temperature (EGT) are 28.2%, 3% and 465 °C respectively. Similarly, reduced emission of CO, NOx, HC and smoke opacity was observed in the CeO2 added blends particularly at 100 mg l−1. It was concluded that among all blends prepared, the D70:WPO30 with 100 mg l−1 of CeO2 showed improved combustion, performance and emission characteristics in proposed diesel engine.

The issue of environmental pollution and the depletion of fossil fuel are nowadays a major field of attention for the modern world. In substitution of petroleum-based diesel, biodiesel and ethanol have been explored in many studies. In this paper, diesel-palm biodiesel-ethanol has been used together at different proportion to execute performanceemission characteristics and their trade-off study at different brake power. An experimental investigation is carried out for different diesel-palm biodiesel-ethanol blends ranging by volume of 5-10% ethanol, 5-25% biodiesel and 65-90% baseline diesel. From the experimental results, comparatively, low brake specific fuel consumption (BSEC) has been observed for all 5% ethanol-blended fuels. Maximum reduction in BSEC has been observed 1.9, 2, and 3.24 % at 0.68, 2.05, and 3.42 kW respectively. At medium to high load, brake thermal efficiency (BTE) has been found higher for lower ethanol fraction. As compared to diesel, the highest nitrogen oxide (NOx) reduction have been found 13.7, 9.17, and 4.7 % at 0.68, 2.05, and 3.42 kW respectively. At last, performance-emission trade-off shows that D70B25E5 blend has a higher BTE with maximum reduction in unburnt hydrocarbon (UHC) and NOx emissions.

The present work investigates the effect of change in combustion chamber geometry on performance and emission characteristics of single cylinder diesel engine fuelled with mahua biodiesel. Since plant oil derived from the mahua tree has high fatty acids, it undergoes esterification followed by transesterification process to reduce its viscosity. Experiments were conducted using a blend of 20% biodiesel (B20) 40% biodiesel (B40) with diesel and compared with diesel by using two types of combustion chamber geometry, explicitly hemispherical and modified hemispherical combustion chamber. Performance parameters such as Brake Thermal Efficiency (BTE), Brake Specific Fuel Consumption (BSFC) and emission parameters like Unburned Hydro Carbon (UBHC), Oxides of Nitrogen (NOx) were studied from the diesel engine with above mentioned configurations. It is obvious that there is considerable improvement in the performance parameter viz, BTE, BSFC and reduction in UBHC emissions by using the modified geometry piston. However, the NOx emission was found to be higher than that of standard configuration. The results obtained from the blend B20 at modified combustion chamber geometry are on par with diesel and hence mahua biodiesel can be suggested as an alternative fuel for Compression Ignition (C.I) engine with modified combustion chamber geometry.

The study represents a comprehensive analysis of engine exhaust emission variation from a compression ignition (CI) diesel engine fueled with diesel-biodiesel blends. Biodiesel used in this investigation was produced through transesterification procedure from Moringa oleifera oil. A single cylinder, four-stroke, water-cooled, naturally aspirated diesel engine was used for this purpose. The pollutants from the exhaust of the engine that are monitored in this study are nitrogen oxide (NO), carbon monoxide (CO), hydrocarbon (HC), and smoke opacity. Engine combustion and performance parameters are also measured together with exhaust emission data. Some researchers have reported that the reason for higher NO emission of biodiesel is higher prompt NO formation. The use of antioxidant-treated biodiesel in a diesel engine is a promising approach because antioxidants reduce the formation of free radicals, which are responsible for the formation of prompt NO during combustion. Two different antioxidant additives namely 2,6-di-tert-butyl-4-methylphenol (BHT) and 2,2'-methylenebis(4-methyl-6-tert-butylphenol) (MBEBP) were individually dissolved at a concentration of 1% by volume in MB30 (30% moringa biodiesel with 70% diesel) fuel blend to investigate and compare NO as well as other emissions. The result shows that both antioxidants reduced NO emission significantly; however, HC, CO, and smoke were found slightly higher compared to pure biodiesel blends, but not more than the baseline fuel diesel. The result also shows that both antioxidants were quite effective in reducing peak heat release rate (HRR) and brake-specific fuel consumption (BSFC) as well as improving brake thermal efficiency (BTE) and oxidation stability. Based on this study, antioxidant-treated M. oleifera biodiesel blend (MB30) can be used as a very promising alternative source of fuel in diesel engine without any modifications.

The present study presented an inclusive analysis of engine exhaust emission characteristics of direct injection diesel engine fuelled with diesel and biofuel. Biofuel used in this investigation was obtained by steam distillation from pine oil. A single-cylinder, four-stroke diesel engine was used for this purpose. In this work, performance characteristics like brake thermal efficiency (BTE) and brake-specific fuel consumption (BSFC) were analysed. The engine pollutants, namely nitrogen oxide (NO), carbon monoxide (CO), hydrocarbon (HC), and smoke, were examined. In addition, combustion characteristics like in-cylinder pressure and heat release rate were presented. Two engine modification techniques, namely thermal barrier coating and the addition of antioxidant to biofuel, were attempted. The advantage of thermal barrier coating is to reduce heat loss from the engine and convert the accumulated heat into useful piston work. In this work, partially stabilised zirconia was used as the coating material. The usage of antioxidant-treated biofuel in a diesel engine was said to be the prominent approach for NOx emission reduction. Three different antioxidants, namely butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), tertiary-butyl hydroquinone (TBHQ), were exclusively dissolved at a concentration of 1% by volume with PO fuel. The obtained performance and emission characteristics of the uncoated engine were compared with the thermally coated engine. From the results, it was observed that the PO biofuel may be a promising alternative in the near prospect with the thermal barrier coating technique to enhance the performance, combustion and emission characteristics of diesel engine. The PO+TBHQ blend was considered as more beneficial than PO+BHT and PO+BHA on account of its performance, combustion and emission characteristics. The effectiveness of the antioxidant was shown in the order of TBHQ>BHA>BHT.

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

In the present study, Artificial Intelligence (AI) based Gene Expression Programming (GEP) is used to develop a model to predict the performance and emission characteristics of a single-cylinder diesel engine fueled with linseed oil methyl ester (LOME) blended with mineral diesel. The data to be used for GEP were obtained experimentally by varying the biodiesel/mineral diesel blending ratio, engine load, fuel injection pressure, and fuel injection timing. The GEP-based model was developed to predict the brake thermal efficiency (BTE), brake specific fuel consumption (BSFC), NOx, and unburned hydrocarbon (UHC) emission. A major part (70%) of the collected data was used for training and remaining (30%) was used for model validation. The developed GEP model was robust enough to provide a high degree of accuracy in the prediction of engine performance and emission parameters. The statistical measure of model robustness such as coefficient of correlation (R) was in the range of 0.9926–0.9999 and the coefficient of determination (R2) was 0.9854–0.9998 for the output prediction. The root mean square error (RMSE) in the GEP model predicted results were in the range of 0.0048–2.597 and mean absolute error (MSE) was 0.0037–4.386. Abbreviations: AI: Artificial Intelligence; BSFC: Brake specific fuel consumption; bTDC: Before top dead center; BTE: Brake thermal efficiency; B0: (MOME 0% + Mineral diesel 100%); B10: (MOME 10% + Mineral diesel 90%); B20: (MOME 20% + Mineral diesel 80%); CI: Compression ignition; CO: Carbon monoxide; ET: Expression tree; FIP: Fuel injection pressure; FIT: Fuel injection timing; GEP: Gene expression programming; ICE: Internal combustion engine; ID: Ignition delay; MAE: Mean absolute error; MIT: Machine identical tool; NOx: Nitrogen oxides; ppm: Parts per million; R: Regression coefficient; R2: Coefficient of determination; RMSE: Root mean square error; UHC: Unburned hydrocarbon

Abstract. Tropospheric ozone is important to future air quality and climate. We investigate ozone changes and ozone sensitivity to changing emissions in the context of climate change from the present day (2004–2014) to the future (2045–2055) under a range of shared socio-economic pathways (SSPs). We apply the United Kingdom Earth System Model, UKESM1, with an extended chemistry scheme including more reactive volatile organic compounds (VOCs) to quantify ozone burdens as well as ozone sensitivities globally and regionally based on nitrogen oxide (NOx) and VOC mixing ratios. We show that the tropospheric ozone burden increases by 4 % under a development pathway with higher NOx and VOC emissions (SSP3-7.0) but decreases by 7 % under the same pathway if NOx and VOC emissions are reduced (SSP3-7.0-lowNTCF) and by 5 % if atmospheric methane (CH4) mixing ratios are reduced (SSP3-7.0-lowCH4). Global mean surface ozone mixing ratios are reduced by 3–5 ppb under SSP3-7.0-lowNTCF and by 2–3 ppb under SSP3-7.0-lowCH4. However, surface ozone changes vary substantially by season in high-emission regions under future pathways, with decreased ozone mixing ratios in summer and increased ozone mixing ratios in winter when NOx emissions are reduced. VOC-limited areas are more extensive in winter (7 %) than in summer (3 %) across the globe. North America, Europe, and East Asia are the dominant VOC-limited regions in the present day, but North America and Europe become more NOx-limited in the future mainly due to reductions in NOx emissions. The impacts of VOC emissions on ozone sensitivity are limited in North America and Europe because reduced anthropogenic VOC emissions are partly offset by higher biogenic VOC emissions. Ozone sensitivity is not greatly influenced by changing CH4 mixing ratios. South Asia becomes the dominant VOC-limited region under future pathways. We highlight that reductions in NOx emissions are required to transform ozone production from VOC to NOx limitation, but that these lead to increased ozone mixing ratios in high-emission regions, and hence emission controls on VOC and CH4 are also necessary.

Tropospheric ozone is important to future air quality and climate. We investigate ozone changes and ozone sensitivity to changing emissions in the context of climate change from the present day (2004–2014) to the future (2045–2055) under a range of shared socio-economic pathways (SSPs). We apply the United Kingdom Earth System Model, UKESM1, with an extended chemistry scheme including more reactive volatile organic compounds (VOCs) to quantify ozone burdens as well as ozone sensitivities globally and regionally based on nitrogen oxide (NOx) and VOC concentrations. We show that the tropospheric ozone burden increases by 4 % under a development pathway with higher NOx and VOC emissions (SSP3-7.0), but decreases by 7 % under the same pathway if NOx and VOC emissions are reduced (SSP3-7.0-lowNTCF) and by 5 % if atmospheric methane (CH4) concentrations are reduced (SSP3-7.0-lowCH4). Global mean surface ozone concentrations are reduced by 3–5 ppb under SSP3-7.0-lowNTCF and by 2–3 ppb under SSP3-7.0-lowCH4. However, surface ozone changes vary substantially by season in high-emission regions under future pathways, with decreased ozone concentrations in summer and increased ozone concentrations in winter when NOx emissions are reduced. VOC-limited areas are more extensive in winter (7 %) than in summer (3 %) across the globe. North America, Europe and East Asia are the dominant VOC-limited regions in the present day but North America and Europe become more NOx-limited in the future mainly due to reductions in NOx emissions. The impacts of VOC emissions on O3 sensitivity are limited in North America and Europe because reduced anthropogenic VOC emissions are offset by higher biogenic VOC emissions. O3 sensitivity is not greatly influenced by changing CH4 concentrations. South Asia becomes the dominant VOC-limited region under future pathways. We highlight that reductions in NOx emissions are required to transform O3 production from VOC- to NOx-limitation, but that these lead to increased O3 concentrations in high-emission regions, and hence emission controls on VOC and CH4 are also necessary.

This thesis investigates the potential of corn oil biodiesel as a renewable alternative fuel for diesel engines. An experimental study is conducted to enhance the engine characteristics of corn oil blended diesel through various approaches, including adjusting the compression ratio, employing different exhaust gas recirculation (EGR) rates, and incorporating Nano additives into the fuel. Preliminary examinations of corn oil methyl ester (COME) blends at 10%, 20%, and 30% reveal that the COME20 blend outperforms the others, establishing it as the preferred blend for further investigation. Subsequently, the investigation proceeds with COME20 at different load and speed conditions. The experimental results demonstrate notable improvements in engine performance. Specifically, at a compression ratio of 20:1 (CR20:1) compared to 18:1 (CR18:1), brake thermal efficiency increases by 2.72%, and brake-specific fuel consumption (BSFC) decreases by 7.8%. Furthermore, significant reductions in exhaust emissions, including carbon monoxide (17.64%), unburnt hydrocarbons (13.8%), and smoke opacity (3.5%), are observed. However, there is an increase in nitrogen oxides (NOx) emissions. In terms of exhaust gas recirculation (EGR), the addition of 6% and 12% EGR to COME20-CR20 results in reduced NOx emissions compared to diesel. Notably, the 12% EGR exhibits a greater reduction in NOx emissions but compromises engine performance to a greater extent than the 6% EGR. In conclusion, this study highlights the potential of optimizing engine design (compression ratio), control (EGR rate), and fuel reformulation (COME biodiesel blending) to facilitate the efficient utilization of COME biodiesel blended diesel fuel in compression ignition (CI) engines. The findings contribute to the advancement of renewable fuel technologies and offer insights for future developments in the field of sustainable transportation. KEYWORDS: Corn oil biodiesel, Renewable alternative fuel, BSFC (Brake-specific fuel consumption), Compression ratio, Exhaust gas recirculation (EGR), Nano additives, COME20 blend

Butanol is considered as the more promising alternative fuel candidate because of its favorable chemical and physical properties over ethanol and methanol. In this study, the performance and emissions of a port fuel injected spark ignition engine fueled with butanol‐gasoline blends (0–60 vol % butanol blended with gasoline referred as G100‐B60), including brake thermal efficiency (BTE), brake specific fuel consumption (BSFC) and carbon monoxide (CO), unburned hydrocarbon (UHC), nitrogen oxide (NOx), were investigated under various equivalence ratio. Among the butanol‐gasoline blends, B30 performs well in engine performance and emissions due to its CO (2.3%–8.7%), UHC (12.4%–27.5%), and NOx (2.8%–19.6%) emissions compared to those of gasoline. Butanol can be a good alternative fuel to gasoline for its potential to reduce pollutant emissions. It is well known that engine tests are hard, time consuming, and high cost. Therefore, support vector regression (SVR) was used to predict the performance and emissions of the engine, where equivalence ratio and blend ratio were used as the input parameters, and BTE, BSFC, CO, UHC, and NOx were used as the output parameters. It was observed that the correlation coefficients and mean relative error were in the range of 0.9940–0.9998 and 0.1901–10.2570%, respectively. The SVR predictions of BTE, BSFC, CO, UHC, and NOx yielded the root‐mean‐squared‐errors of 0.0511%, 4.6058 g/kW h, 0.9995% vol, 7.7503 ppm vol and 38.5861 ppm, respectively. It could be indicated that the SVR provided an accurate and simple approach to analyze performance and exhaust emissions of spark ignition engine. © 2018 American Institute of Chemical Engineers Environ Prog, 38:e13042, 2019

Considerable efforts have been made to introduce alternative fuels for use in conventional diesel and gasoline engines. There is significant interest in adding hydrogen to a diesel engine to reduce emissions and improve efficiency. However, the main challenge associated with the use of hydrogen in diesel engines is high nitrogen oxide (NOX) emissions. In the present study, a reduced chemical kinetics mechanism, consisting of 52 reactions and 29 chemical species for n-heptane fuel combustion, was incorporated with detailed chemical kinetics consisting of 29 reactions for hydrogen as well as additional nitrogen oxidation. This reaction mechanism was coupled with 3-D advanced CFD software to investigate the performance and emission characteristics of a diesel-hydrogen dual-fuel engine. Computational results showed good agreements with the experimental results for brake thermal efficiency, CO2, CO, and NOX emissions. The model was then employed to examine the effects of exhaust gas recirculation (EGR) and N2 dilution on NOX emissions. The computational results quantified the reduction in NOX emissions with EGR and N2 dilution, and a more remarkable reduction was found with 30% N2 dilution. However, in terms of the N2 dilution, a general decreasing trend was observed for both NOX and CO2 emissions, while CO emissions increased. In relation to the EGR, the NOX emissions decreased while CO2 and CO emissions significantly increased. Additionally, the results showed that the indicated mean effective pressure (IMEP) and indicated power decreased as the N2 dilution increased. The same trend was observed for the EGR but the reduction was less compared to that of the N2 dilution.

The present work investigates the effect of using TiO2 Nanoparticles at a different proportion of Azolla algae methyl ester, in a four-stroke single cylinder diesel engine. Biodiesel can be obtained from Azolla algae due to the presence of high oil content. The oil was extracted from Azolla algae by means of the Soxhlet extraction method which was compared to be more effective than the oil obtained by means of hydraulic pressing machine. The obtained oil was converted to biodiesel by means of transesterification process. The fuel properties of the prepared Azolla methyl ester found to confirm with the ASTM standards. TiO2 Nanoparticles were synthesized by means of ball milling process and characterized by means of Scanning Electron Microscope (SEM), Atomic Force Microscopy (AFM), Fourier Transform Infrared (FTIR) and X-Ray Diffraction (XRD) techniques. In the present study, the performance and emission characteristics of diesel engine were analyzed with the addition of TiO2 Nanoparticles to Azolla oil methyl ester (25,50,75 and100 ppm) and compared with that of diesel. The % decrease in Brake Specific Fuel Consumption (BSFC) for B20 + 25, B20 + 50, B20 + 75 and B20 + 100 were found to be 7.81, 12.05, 19.71, and 23.53, respectively, when compared to B20. The % increase in Brake Thermal Efficiency (BTE) for B20 + 25, B20 + 50, B20 + 75 and B20 + 100 were found to be 2.60, 8.49, 8.79 and 13.38, respectively, when compared to B20. The % decrease in Carbon monoxide (CO) for B20 + 25, B20 + 50, B20 + 75 and B20 + 100 were found to be 21.15, 51.92, 54.80, and 57.30, respectively, when compared to B20. The % decrease in Hydro Carbon (HC) for B20 + 25, B20 + 50, B20 + 75 and B20 + 100 were found to be 7.53,8.36,10.04 and 12.97, respectively, when compared to B20. The % increase in Oxides of Nitrogen (NOx) for B20 + 25, B20 + 50, B20 + 75 and B20 + 100 were found to be 5.44, 7.85, 8.67, and 9.16, respectively, when compared to B20. The % decrease in smoke for B20 + 25, B20 + 50, B20 + 75 and B20 + 100 were found to be 18.02, 30.18, 31.98 and 36.04, respectively, when compared to B20. Addition of TiO2 Nanoparticles with the Azolla biodiesel is found to be an effective approach to improve the performance and emission characteristics of a diesel engine without any modification.

The current work implies the influence of copper chloride (CuCl2) and cobalt chloride (CoCl2) nanoparticle dosed diesel-linseed oil biodiesel blend (B20) to assess the performance and emissions characteristics of a direct injection diesel engine. Three distinct proportions of nanoparticles were added to B20, namely 50, 75, and 100 ppm independently for CuCl2 and CoCl2. QPAN 80 dispersant was added to nanoparticles at a quantity of 100 ppm and played out an ultrasonication process. The stability test was performed in two particular periods like Day1 and Day 15. The performance concerning brake thermal efficiency (BTE) was enhanced with nanoparticle (CuCl2 and CoCl2)-dosed dispersant-mixed B20. Similarly, the brake-specific fuel consumption (BSFC) was also specified less. Besides, the emissions of carbon monoxide (CO), unburnt hydrocarbons (UHC), nitrogen oxides (NOx), and smoke emissions were seen lower with the nanoparticle addition. At the utmost load, the maximum BTE was improved by 8.28 and 5.06%, while the BSFC was reduced by 1.42 and 0.91%, respectively, for B20 + 75 ppm CuCl2 + dispersant and B20 + 75 ppm CoCl2 + dispersant. Similarly, the CO, UHC, NOx, and smoke were dropped down drastically for B20 + 75 ppm CuCl2 + dispersant by 65.7, 22.7, 40.37, and 15.5%, respectively, while for B20 + 75 ppm CoCl2 + dispersant, it was decreased by 57.1, 24.5, 39.08, and 10.07% respectively.

The developments in the field of nano-additives have increased in the recent years due to the desire to reduce the level of exhaust emissions in diesel engines. The soot characteristics of particulate matter (PM) and nitrogen oxides (NOX) were experimentally investigated using two concentrations of titanium dioxide (TiO2) as nano-additives (25 ppm and 40 ppm) blended with C20D (composed of 20% castor oil methyl ester and 80% diesel fuel) and 30% exhaust gas recirculation (EGR). The combustion of C20D + TiO2 increases brake thermal efficiency (BTE) by 2.8% in comparison with neat C20D, while a significant reduction was obtained in BSFC 6.5% and NOX emissions were maintained at a level parallel with diesel. The results indicated that the technique involving a high EGR rate and the addition of 25 ppm and 40 ppm of TiO2 nanoparticles to the C20D exhibits better reductions in NOX emissions by 17.34% and 21.83%, respectively, compared to the technique comprising the use of C20D + TiO2 and C20D. The reduction in the total concentration of PM via the addition of TiO2 nanoparticles to the C20D was 26.74% greater than neat C20D and diesel. In contrast, the incorporation of a high rate of EGR with C20D +TiO2 increased the PM concentrations by 16.85% compared to the technique without EGR. Furthermore, the high concentrations of TiO2 nanoparticles (40 ppm) in the C20D produced 19 nm smaller soot nanoparticles compared to the 23 nm larger soot nanoparticles produced from the low concentrations of TiO2 nanoparticles (25 ppm) added into the C20D. The current investigation reveals that the reduction in NOX emissions and the production of soot nanoparticles notably improved due to the synergic effect of EGR, the TiO2 nanoparticles, and biodiesel.