HC Emissions Research Articles

Reducing the Harmful Exhaust Emissions from the Diesel Engine of the Tractor CASE JX75T by using the EFWP Filter at Different Engine Speeds

In this investigation, the influence of using the EFWP filter on the tractor exhaust emissions was determined. A Water and paper filter is a filter designed to operate as a filter for the exhaust for the reduction of the harmful gas (CO, CO2, NOx, and HC) emission from the engine of the tractor. Emissions experiments were carried out on CASE JX75T tractor at different engine speeds are 750, 1000, 1250, 1500, 1750, 2000, and 2250 rpm. All engine speed of the tractor underwent experimentation before the installation of the EFWP filter and after installation it. The noises and Bsfec also were measured when the two cases. Each engine speed was tested for approximately 20 minutes in two cases. The results showed a significant (P≤0.05) decreasing in carbon monoxide CO (51.40%), carbon dioxide CO2 (25%), nitrogen oxides NOx (43.43%) and hydrocarbons HC (60.98%) emissions and also, the noises reduced by 25.38% and there was no significant increase in the BSFC (5.34% only) after the EFWP filter was put in the tractor exhaust. The results also showed that increasing the engine speed from 750 to 2250 rpm led to significant increases in CO2, NOx, and HC emissions, while decreased the CO emission. Also, the increased by a percentage of 155.88 and 159.38 % in the case using the EFWP filter and without using it (the ordinary case) respectively. Using the EFWP filter reduced the noises not overridden internationally permitted standards (65 dB).

Effect on minor addition of aromatic (benzyl alcohol) and diethyl ether in Calophyllum inophyllum blended diesel fuel in a CI engine operates by hydrogen energy as a secondary fuel

Strict regulations on vehicle emissions are in place to lessen pollution and environmental damage. The depletion of fossil fuels also threatens energy security. Renewable, cleaner-burning and sustainable fuels could aid the researcher in solving these problems. Because of their limited supply, renewable fuels cannot resolve the issue independently. Therefore, much research is being done on enhanced combustion technologies, such as dual-fuel engines, homogenous charge compression ignition, and low-temperature combustion. The Calophyllum inophyllum oil (P20) mixed with diesel, diethyl ether, and aromatic alcohol (benzyl alcohol) was tested in this study using a dual-fuel engine. Hydrogen gas is added to the air intake manifold as a second energy source. Aromatic alcohol is an organic fuel that can be produced naturally by hydrolysis of lignin. The OH hydroxyl group is attached to the aromatic ring and promotes free radical propagation. Minor addition of oxygenates affects the performance, combustion, and emission of engines operating on various loads. Maximum brake thermal efficiency and lower brake-specific fuel consumption were observed with 20 % aromatic alcohol, 32.45 %, and 0.2 kg/kW-hr, respectively. Brake thermal efficiency improved to 6.54 % compared to neat diesel. Reduction in brake-specific fuel consumption by 28 % compared to diesel fuel. Compared to other blends, aromatic alcohol additions are linked to reduced smoke, HC, and CO emissions. However, using aromatic alcohol results in slightly increased nitrogen oxide emissions compared to diesel. Blends of biofuel and benzyl alcohol have shown favorable effects in terms of enhanced combustion, reduced emissions, and increased efficiency.

Experimental investigation of hydrogen combustion in a single cylinder PFI engine

The simultaneous reduction of Green-House Gases (GHG) and criteria pollutants is the main target of current Internal Combustion Engines (ICE) development. Hydrogen (H2) fueling is one of the best options available in both regards, as it does not emit tailpipe CO2 as well as significantly abates all criteria pollutants already at engine-out level. However, optimizing hydrogen combustion in order to exploit the fuel proprieties at best is a challenging task due to the very particular properties of the fuel. In fact, H2 combustion in ICE promotes a very clean, fast and complete combustion process, with extremely low HC, CO, and PM engine-out emissions stemming only from lubricant oil. The usage of lean-boosted and EGR-diluted combustion strategies can significantly contribute to raise the brake thermal efficiency and lower the NOx emission to extremely low levels. To this end, the Authors tested a 0.5 L single cylinder engine featuring an optimized PFI layout and dedicated piston bowl profile for a retrofitted Diesel operating as H2 monofuel, in SI mode. In this paper, the authors discuss the effect of the main engine parameters, extensively investigated by means of Design of Experiments (DoE) techniques, as well as the effect of dilution and EGR to promote clean and efficient hydrogen combustion, in order to recommend the most effective practices.

Assessing the emissions of short sea international shipping: a case study of the Mytilini–Ayvalik route

Short sea shipping involves transporting passengers and cargo between European ports and coastal countries bordering Europe on enclosed seas. Challenges include aging fleets and environmental concerns, but efforts to reduce emissions are in progress through the use of low-sulfur fuels, hybrid and electric vessels, and improved energy efficiency. This study focuses on emissions from international short shipping routes between Mytilini and Ayvalik, using standardized emission factors to calculate CO2, SO2, NOx, PM, and HC emissions. The research aims to bridge knowledge gaps and provide insights into these emissions, identifying the main commercial ships on the route, analyzing their emissions, and discussing the findings. Overall, six ships completed the route, consuming an average of 60 L of fuel per hour per 100 HP, depending on factors like speed and total load. Notably, NOx emissions are the highest, followed by sulfur oxides, with values exceeding 12.9 and 3.5 tons, respectively. As anticipated, cruising is the shipping practice with the highest energy footprint, amounting to 695 MWh. An essential discovery is that hoteling plays a significant role in energy consumption and emissions, accounting for 152 MWh out of the total 881 MWh consumed across all shipping practices. The potential adoption of hydrogen as a fuel holds the promise of substantial reductions in greenhouse gas emissions, enhancements in air quality, and noise pollution mitigation.

Effect of nanoparticles (Al2O3 and CeO2) blended with biodiesel on combustion, performance, and emissions of a diesel engine

The increase in the utilization of fossil fuels in almost all the energy production sector badly impacts the environment because of incomplete combustion. The incomplete combustion of fuels releases soot, unburned hydrocarbon, and greenhouse gas emissions, contributing significantly to climate change. In the current experimental work, the evaluation of the effect of the addition of aluminium oxide (Al2O3) and cerium oxide (CeO2) nanoparticles in Jatropha biodiesel (B20) has been performed on the combustion, performance, and emission characteristics of compression ignition engine. These nanoparticles have been added because they have a large surface area-to-volume ratio. The air-fuel mixture and the evaporation rate are enhanced, leading to improved burning. The increase in brake thermal efficiency has been observed with nanoparticles blended fuel, i.e. (B20 + 30 ppm Al2O3 + 30 ppm CeO2) by 9.354%. In contrast, drop-in oxides of nitrogen, carbon monoxide, HC, and smoke opacity emissions were observed by 24.67%, 33.33%, 23.08%, and 34.01%, respectively, compared with pure biodiesel. Using nanoparticles in Jatropha methyl ester reduces ignition delay, increases combustion duration, and starts earlier combustion, reducing heat release rate, cylinder pressure, and pressure rise rate by 10.53, 1.994, and 3.687%, respectively, as compared to the B20 blend.

Efficacy of performance and mitigate pollution of CI engine: Delonix regia biodiesel with n‐butanol and exhaust gas recirculation

AbstractThe primary aim of this research study was to examine the effectiveness and environmental consequences of using Delonix regia biodiesel (DRB) in combination with butanol (BUT), exhaust gas recirculation (EGR), and diesel fuel (D) on a direct injection compression ignition engine operating at a constant speed. This study involved the formulation of five distinct biodiesel blends, namely DRB10% + D90%, DRB20% + D80%, DRB10% + BUT10% + D80%, DRB10% + BUT20% + D70%, and DRB20% + D80% + EGR10%. The inclusion of n‐butanol in a biodiesel blend serves to tackle the problem of inadequate combustion in fuel blends by alleviating the oxygen deficiency that occurs during the combustion process. The findings of the study revealed that the combination of DRB at 10%, BUT at 20%, and D at 70% produced in a significant reduction in specific fuel consumption (SFC) by 11.19% and brake thermal efficiency by 2.62%. Additionally, this combination led to a decrease in exhaust emissions of CO and Smoke, with the exception of HC and NOx, when compared to the use of diesel fuel. The control of HC and NOx emissions can be achieved through the implementation of an exhaust gas recirculation system. The results of this investigation suggest that Delonix regia biodiesel, in combination with a 20% concentration of n‐butanol, has potential as a viable alternative fuel choice that may be utilized without necessitating any engine modifications.

Prediction modeling using artificial neural network (ANN) for the performance and emission characteristics of catalytic co-pyrolytic fuel blended with diesel in a CI engine.

In the present research work, artificial neural network (ANN) is used to model the performance and emission parameters in a four-stroke, single-cylinder diesel engine combusting a blended fuel of diesel and catalytic co-pyrolysis oil produced from seeds of Pongamia pinnata, waste LDPE, and calcium oxide catalyst. The optimum yield of oil obtained was 92.5% at 500 °C temperature. Physical properties of the obtained oil, such as calorific value (44.85 MJ/kg) and density (797 kg/m3), level it by that of diesel while the flash point and fire point were found to be lower than that of pure diesel. An ANN model was then generated for the prediction of performance characteristics (BTE and BSFC) and emission characteristics (NOx and smoke) under varying loads, braking power, brake mean effective pressure, and torque as inputs using the Levenberg-Marquardt back-propagation training technique. The regression coefficients (R2) for BTE, BSFC, smoke, and NOx predictions were determined to be close to unity at 0.99859, 0.99814, 0.96129, and 0.92505, respectively (all values being close to unity). It has been discovered that ANN makes an effective simulation and prediction tool for blended fuels in CI engines. It is also suggested to predict the mechanical efficiency, volumetric efficiency, and CO, CO2, HC emissions using ANN in its future work.

Experimental investigation on the influence of H2 on diesel engine fueled with Afzelia Africana biofuel – Titanium oxide nanoparticle blends

Diesel engines are a major source of air pollution, which is increasingly endangering both the natural and built environments. The use of H2-enrichment with nano-fuel was adopted in this research. The TiO2-nanoparticles- Afzelia-Africanabiodiesel was blended with H2 for use in diesel engine. 25 ppm of TiO2 nanoparticles was admixed with the biofuel and ultrasonicated. After that, H2 was introduced through the intake air at different flowrates. The ratio of H2 to the blended fuels (BNH) is (15:85 vol/vol%). The effects of the blends with H2 on emission/performance characteristics were investigated by evaluating NOx, CO, and HC emissions and brake thermal efficiency-(BTE). Higher BTE blends with hydrogen flowrate of 3 LPM improved the engine performance with lesser emissions. Sample blend with hydrogen flowrates of 3LPM gave the best performance/BTE of 39.4 %.The nano-fuel BN@25 + H2 (3 LPM) recorded the lowest emissions (81, 0.33 and 5 g/kWh) at full load when compared with the diesel (129, 0.63 and 20 g/kWh) in terms of NOx, CO, and HC. The in-cylinder pressure and heat release rates of the biodiesel significantly improved H2 addition to TiO2 -NPs by 10 and 14 % relative to diesel. Therefore, the H2-enrichment with the nano-fuel displayed a positive effect on the engine without further modifications.

Effect of Dwell Angle and Two-Stage Fueling Approach on the Engine Parameters of CRDi Engine using WCO Biodiesel Blends

In this paper, the impact of dwell angle and two-stage fueling technique on engine efficiency and tailpipe emissions in a 3.5 kW powered four-stroke diesel engine fueled with waste cooking oil (WCO) biodiesel blends were investigated. An experiment with single-cylinder high-pressure CRDi equipped diesel engine was executed at two different dwell angles (5° CA and 10° CA) with varying pilot fueling quantities of 10% and 20% at nozzle fueling pressure of 600 bar. The outcomes revealed that the combined effect of dwell angle and two-stage fueling techniques had enhanced the BTE by 8.13% for B20P20 pilot fueling timing (PFT) of 28° bTDC, whereas BSFC lowers for B20P20 blend at pilot fueling timing of 33° bTDC. Comparing B20P20 PFT at 28° bTDC to PFT at 33° bTDC, CO, HC and smoke emissions drop by 72.72%, 37.04%, and 93.75%, respectively. The nitrogen oxide reduction is unaffected by two-stage fueling strategy among all the test sample fuels and significantly higher for the biodiesel blends than mineral diesel.

Assessment of Performance and Emission Characteristics using Algae Biodiesel in an Additive Fuelled LHR Engine

Automobiles use compression-ignition (CI) engines because they have more pulling power, are more dependable and use less fuel than spark-ignition (SI) engines. Both CI and SI engines use petroleum-based oils, contributing to environmental pollution like acid rain, ozone depletion and climate change. The cost of petroleum-based fuel is increasing daily due to demographic growth and the development of manufacturing industries. There are four phases to the experiments. The first stage involves mixing diesel with 20% of ALME, the outcomes showed that engine operation and combustion are comparable to conventional diesel fuel. In the second stage, an LHR engine tests 20% of ALME and the results showed that BTE of LHR engine had significantly increased. In comparison, NOx increases in LHR-operated CI engine, CO, HC and smoke emissions are significantly lower than with a conventional engine. The third stage looks at how NA interacts with biodiesel to affect conventional engine’s combustion, emission and engine performance. The prepared algae biodiesel is blended with NA in various ratios of 500ppm, 1000ppm, 1500ppm and 2000ppm. At 1000ppm concentration, NOx emission from conventional and LHR engines has been effectively minimized under load conditions. Concerning diesel fuel, emissions like CO, HC and smoke are significantly reduced for all loads. In the fourth stage, tests on the LHR engine are carried out using the SBME with NA in various proportions. When compared to base fuel, it has been found that NOx emission has decreased significantly at 1000ppm compared to conventional engines and other emissions have decreased.

Injection strategy of methanol for high loads and low NOx emissions in a neat methanol LTC engine

Methanol is a low carbon and clean burning renewable fuel. Though low temperature combustion (LTC) of neat methanol results in almost no smoke with ultra-low NOx, the extremely low cetane number poses challenges. This experimental study demonstrates LTC of neat methanol at full load by combining direct and port injection of this fuel with controlled intake air temperature (IAT). The effects of important variables including IAT and port (premixed) and direct-injected methanol shares on combustion, performance, regulated and unregulated emissions were investigated. The timing of the direct-injected methanol had to be retarded with an increase in the premixed methanol share and IAT in order to limit the pressure rise rate without affecting the ITE. At high IATs, the premixed methanol burned first, followed by the directly injected methanol, at low IATs, these phases merged, resulting in a high rate of heat release. Employing the lowest possible IAT and the highest possible premixed methanol share led to high ITE. Increase in the MDIP to 450 bar was advantageous due to better fuel evaporation and enhanced combustion. Negligible smoke, very low NOx of 2.7 g/kWh, high ITE of 45% and unburned HC and methanol emissions lesser than 3 g/kWh could be achieved.

Synergic effect of hydrogen and n-butanol on combustion and emission characteristics of a hydrogen direct injection SI engine fueled with n-butanol/gasoline

Hydrogen, an ideal carbon-free energy carrier with favorable combustion properties, has drawn worldwide attention as a high-expectation way to enhance fossil fuels’ combustion performance. However, currently, limited investigations are about enhancing n-butanol hybrid gasoline engines through hydrogen addition. Thus, in this paper, the hydrogen direct injection (HDI) was put forward to improve an SI engine fueled with n-butanol/gasoline, and the synergic effect of hydrogen and n-butanol on combustion and emission characteristics was studied. Experimental results indicated the favorable influence of a low n-butanol mixing ratio (νN, νN = 25%) on enhancing combustion can relatively weaken the similar promoting effect of hydrogen. And the sequential increase in hydrogen addition ratio (φH, φH = 15–20%) can compensate for the negative impact of unfavorable atomization and vaporization quality caused by higher n-butanol blending (νN = 75–100%), namely the usage amount of n-butanol in engine can be raised. Further, compared with pure gasoline, the percentage change in BMEP (brake mean effective pressure) at νN = 25% and 100% can be increased from 1.79% to 5.04% and −5.38%–2.01% respectively by φH from 0 to 20%. Besides, the HDI can also shorten the combustion duration, accelerate the heat release process and improve the combustion stability of each νN, while the amplitude of promotion exhibits a relative downtrend with the increase of φH. As for emission characteristics, the HC, CO and particulate emissions decreased monotonously with the increasing φH under all νN, but there was a visible increase in NOX emissions.

Performance and Emission Comparison of Different Test Fuels in a Compression Ignition Engine with Syngas and Pyrolytic Oil Derived from Safflower

ABSTRACT This work aimed to compare the performance and emissions of different test fuels in a compression ignition engine. The fuels included diesel, SFEEE20, and SFME20, with and without a diesel reforming and partial oxidation system. Syngas and pyrolytic oil produced from Safflower were used in single and dual fuel modes. The results showed that brake thermal efficiency (BTE) increased in dual fuel mode compared to single fuel mode. Diesel with SFS exhibited the highest efficiency of 32.20%, followed by SFEEE20 with SFS at 31.91% and SFME20 with SFS at 31.08%. The specific fuel consumption (SFC) decreased in dual fuel, and at maximum load condition, SFME20 with SFS demonstrated the lowest SFC of 0.3193 kg/kW-hr in dual fuel mode. SFEEE20 with and without SFS displayed SFC values of 0.28051 kg/kW-hr and 0.3005 kg/kW-hr, respectively. At maximum load condition, SFME20 with SFS exhibited an EGT of 187°C, while PME and diesel with SFS showed EGT values of 183°C and 184°C, respectively. CO and HC emissions decreased in dual fuel mode compared to single fuel mode. The work concluded that SFEEE20 with SFS showed promising results with high BTE and low emissions, making it a potential fuel blend for compression ignition engines.

Study on combustion and emissions characteristics of acetone-butanol-Ethanol(ABE)/gasoline premixed fuel in CISI engines

ABE (acetone-butanol-ethanol) was a clean biomass substitute fuel. This paper investigated the combustion and emission performance of ABE/gasoline premixed fuel Combined Injection Spark Ignition engine with various ABE ratios and direct injection ratios. Thus exploring the potential of ABE/gasoline premixed fuel for use in combined injection engines. Results showed that high ABE ratios (≥75 %) can increase maximum cylinder pressure and BMEP by 3.8 % at least with various direct injection ratios (except P0G100), and increasing the duration of the flame development by 28.7 % at least. With different ABE ratios, the duration of the flame propagation increased by 17.1 % at least and maximum heat release rate decreased by 15.8 % at least as the direct injection ratio increased from 0 % to 100 %. With various ABE ratios, using high direct injection ratios (≥75 %) would increase HC emissions by 1.3 % at least, decrease CO emissions by 3.8 % at least and decrease NOx emissions by 11.0 % at least compared to P100G0. Particle Numbers increased with increasing direct injection ratios under different ABE ratios, and reached the minimum value at ABE100 with certain direct injection ratios (≥25 %). Moreover, increasing the ABE blended ratio reduced the number of particles obtained from fuel combustion emissions (except P75G25).

Syngas production from aqueous phase reforming of glycerol–water mixture for compression ignition engine

Syngas produced from glycerol using aqueous phase reforming for nickel-based catalysts with different support materials were tested in a compression ignition (CI) engine. Experiments were conducted using nickel–alumina, nickel–lanthanum (NL), and nickel–ceria catalysts at 1:1, 1:2, 1:3, and 1:4 glycerol–water ratios and temperatures of 240°C, 260°C, and 280°C. The NL catalyst showed the highest syngas and hydrogen yield of 90.58% and 76.42%, respectively, at 1:3 ratio and 260°C. The optimized NL syngas and diesel were tested in a CI engine at 6 to 30 lpm flow rates. At 30 lpm flow, brake thermal efficiency increased by 3.15%, NOx emission was reduced by 21.22%, and smoke lowered significantly compared to diesel. The faster hydrogen combustion in syngas increased the heat release rate and cylinder peak pressure. CO and HC emissions increased at lower loads due to diluted combustion but reduced at higher loads. NL showed the best performance and emissions among the syngases due to higher hydrogen content. In summary, the NL syngas at 30 lpm showed great potential in CI engines by improving combustion and performance and reducing emissions.

Examination of the effect on the engine of diesel-nanoparticle mixture with natural gas addition

Diesel engines have a broader application area and have a significant share in the transportation sector. Although there are restrictions on producing within the scope of emission standards, diesel fuel will remain important in heavy-duty vehicles for some time. Therefore, studies continue for environmentally friendly combustion and low emissions in diesel fuel. This paper reveals the results of using nanoparticle fuel with natural gas (NG) on diesel engine emissions and performance. In the experiments, the motor load was adjusted from no to full load by increasing it at 25% intervals. Three different diesel-nanoparticle blends containing 25 ppm, 50 ppm and 75 ppm carbon nanotube (CNT) were prepared and each of these blends was tested both with and without NG. In light of the test results, it has been seen that the D75ppmCNT + NG mixture is the best fuel mixture compared to both diesel and nanoparticle-added diesel since it provides the highest value in brake thermal efficiency (BTE) and the lowest value in brake specific fuel consumption (BSFC) at full load conditions. In the case of using a D75ppmCNT mixture, around 29% decrease in BSFC and about 28% increase in BTE were observed according to the diesel fuel use. In terms of emissions, when NG is added to the D + CNT fuel mixtures, there is an increment in CO and HC emissions and a slight reduction in NOx emissions at low and medium load.

Experimental Research With Diethyl Ether on Engine Performance and Emissions in a Spark Ignition Engine

In this study, the influences of the diethyl ether addition into pure gasoline were re-searched experimentally in a single cylinder, four stroke, air-cooled spark ignition engine. Experiments were conducted at wide-open throttle and different engine speeds of 2400, 2800, 3200, 3600 and 4000 rpm. The effects of diethyl ether as an additive on engine torque, specific fuel consumption (SFC), thermal efficiency, CO, CO2 and HC emissions were observed. Test results presented that engine torque and power first increased and then decreased with the addition of diethyl ether. SFC increased by about 4.18%, 7.44%, 11.39% and 14.41% with DEE10, DEE20, DEE30 and DEE40 compared to pure gasoline at 2800 rpm respectively. Remarkable reduction were observed on CO and HC emissions with the addition of diethyl ether into gasoline. CO was reduced by 0.67%, 3.39%, 10.61% and 11.11% with DEE10, DEE20, DEE30 and DEE40 compared to gasoline at 4000 rpm respectively. Similarly, HC decreased by 3.70%, 8.82% and 10.58% with DEE20, DEE30 and DEE40 compared to gasoline at 4000 rpm respectively. It was seen that diethyl ether can be used as an additive without modification in spark ignition engines

Optimization of Diesel Engine Performance and Emissions Characteristics with Tomato Seed Blends and EGR Using Response Surface Methodology

The impact of load, Tomato Methyl Ester (TME), and Exhaust Gas Recirculation (EGR) enriched diesel on engine performance and exhaust gas emissions was examined in this study using the Response Surface Methodology (RSM) optimization technique. TME blend biodiesel (20, 40, and 60%) and EGR (10, 20 and 30%) were selected to maximize BTE and minimize BSFC, NOx, CO, smoke, and HC. The engine was operated using the RSM technique by load (0–100%). The results showed that the response variables were significantly influenced by load, TME and EGR concentration of engine. The results of the constructed quadratic models' analysis of variance (ANOVA) suggested that each model was an appropriate fit. Additionally, an optimal was found by optimizing the user-defined historical design of an experiment. The responses corresponding to optimal study factors were load 100%, TME Blend 20 and EGR 10% gives maximum BTE of 32.5%. The fuel consumption 0.2 kg/kW.h is reduced when load 50%, TME Blend 60 and EGR 10%. Smoke and NOx emissions were decreased by 15.09% and 49.04%, while CO and HC emissions were increased by 27.54% and 21.76%

A hybrid RSM-GA-PSO approach on optimization of process intensification of linseed biodiesel synthesis using an ultrasonic reactor: Enhancing biodiesel properties and engine characteristics with ternary fuel blends

The depletion of fossil fuels necessitates the development of sustainable and energy-efficient techniques for biodiesel production. In recent years, cavitation reactors have emerged as a viable alternative to conventional biodiesel synthesis methods due to their superior conversion rates and shorter processing times. These reactors possess a high surface-to-volume ratio and facilitate efficient heat and mass transfer. This study aims to optimize the production of biodiesel from linseed oil using a novel ultrasonic cavitation reactor through a hybrid approach. In order to achieve this, an L50 orthogonal array with five factors and three levels was developed using a Box-Behnken design based on response surface methodology (RSM). These factors included the molar ratio (4:1, 6:1, and 8:1), ultrasonic power (100, 125, and 150 W), temperature (25, 35, and 45 °C), time (3, 6, and 9 min), and ultrasonic frequency (25, 30, and 35 kHz). The parameters were optimized using RSM-based desirability, genetic algorithm (GA), and particle swarm optimization (PSO) approaches. The results indicated that the RSM-based optimization approach outperformed the other methods. The optimal combination of parameters obtained through RSM consisted of molar ratio of 6.58:1, ultrasonic power of 133.65 W, temperature of 37.44 °C, time of 7.71 min, and pulse frequency of 26.29 kHz. This combination resulted in a biodiesel yield of 95.25%. Furthermore, this study explored the impact of different linseed oil methyl ester, octanol, and diesel blends (B10, B20, B30, B10 (O-10), and B20 (O-10)) on engine performance and emission characteristics. The B20 (O-10) blend exhibited significant potential for simultaneously reducing emissions and enhancing engine performance. When used as engine fuel, the B20 (O-10) blend increased brake thermal efficiency (BTE) by 0.848%, decreased brake specific fuel consumption (BSFC) by 0.607%, and decreased CO, HC, and NOx emissions by 18.75%, 6.55%, and 0.72%, respectively, compared to pure diesel at rated power.

Evaluating the real-world emissions of diesel passenger Car in Indian heterogeneous traffic.

A 30 portable emission measurement system (PEMS)test was conducted in this study to examine the effect of driving modes (aggressive and normal) and road type (urban and rural) on tailpipe emissions. Driving modes were assessed using relative positive acceleration and velocity × positive acceleration factors. The findings revealed that aggressive and normal driving modes differed significantly on urban and rural roads, as evident from paired sample t-test (p < 0.05). Furthermore, aggressive driving exhibited more prominent speed and acceleration on rural roads, while normal driving modes showed consistent acceleration or speed patterns regardless of road conditions as observed from kernel density estimation and box plot analysis. Emission rates (CO, CO2, HC, and NOx) significantly varied between aggressive and normal driving modes on urban and rural roads, as indicated by paired sample t-test analysis (p < 0.05). Aggressive driving increased CO2, CO, and HC emission rates for acceleration and deceleration modes by 18% to 40% compared to normal driving. Aggressive driving modes increased the emission factors (CO, HC, and CO2) by 5% to 25% compared to the normal driving mode on both urban and rural roads. Moreover, the NOx emission factors were also found significant during normal driving conditions on urban roads. This study provides real-world emission factors of diesel cars considering the impact of route, vehicle familiarity, and driving behavior induced by varying traffic conditions, which will contribute to improve the current emissions inventory on both a local and global level.