Exhaust Emission Characteristics Research Articles

Characteristics of exhaust emissions from MGO–bioethanol fuel blend using a combustion chamber

We conducted combustion tests with marine gas oil (MGO) blended with bioethanol (BE) in ratios of 0%–30% to address International Maritime Organization air pollution regulations on exhaust gases emitted from ships and fossil fuel resource depletion and achieve carbon neutrality. We designed and manufactured a standard 1-ton combustion chamber, using an attached gun-type burner to analyze the exhaust gases of each sample under similar conditions. Compared to pure MGO (BE0), the oxygen content increased by approximately 1.91% at the maximum blend ratio (BE30), while carbon dioxide decreased by 1.39%. Nitrogen oxides were reduced by approximately 30%. Sulfur oxides were minimal (<0.03%), with MGO alone at approximately 0.08 ppm, confirming the superior quality of low-sulfur fuel. In all blends containing BE, no sulfur oxides were detected. Additionally, exhaust gas temperature decreased by 5.8%, and combustion efficiency decreased from 72.24% to 70.33%, a reduction of approximately 1.9%. This indicated that BE has a relatively lower calorific value; however, it provides a similar thermal output, with some reduction of exhaust emissions. A one-way ANOVA and post-hoc verification confirmed that with increased BE content, emission differences were significant ( p < 0.01 level in all areas). Through this study, it was confirmed that the use of eco-friendly fuels such as bioethanol has excellent effects on reducing exhaust emissions. It is analyzed that it would help solve global warming and air environment pollution problems. Therefore, it is determined that the future application of MGO-bioethanol blended fuel as an eco-friendly alternative fuel for ships holds significant potential, and positive outcomes are anticipated.

Applying similar modeling to study vehicle exhaust transport in a confined mining space

To scientifically and effectively manage exhaust pollution in underground confined spaces and reduce hazards from personnel exhaust exposure, a systematic study of the distribution characteristics of diesel locomotive exhaust emissions in mines is needed. Aiming at large underground coal mining operations, an experimental platform for the physical simulation of vehicle exhaust transport in restricted spaces is designed and created. The Hongliulin Coal Mine in Shaanxi Province, China, is used as a prototype, and the platform consists of a coal mining face system, ventilation system, exhaust emission system, monitoring and surveillance system, and control platform. The experimental platform with carbon dioxide simulation of diesel exhaust pollution, in the role of different wind speed, the concentration of carbon dioxide is a downward trend, the wind speed is in the low wind speed on the 0.2 m of the concentration difference of 25.75%; the experimental platform exhaust transport process presents a clear “three-zone” change rule; experimental platform carbon dioxide concentration and the field nitrogen dioxide concentration change trend is consistent. The platform functions and features can provide guidance for mine exhaust management and exhaust exposure hazard prevention and control.

Evaluation of soot emission and wall heat loss for the fuels with high aromatic contents using the coupled analysis of chemical luminescence images with heat flux

The stricter regulations on the sulfur content of marine fuel oil in the general sea area that came into effect in January 2020 have led to a prediction of the increase of light cycle oil with high aromatic contents. The higher aromatic content is expected to result in higher soot in the exhaust gas. During combustion, soot emits radiant heat because of blackbody radiation, some of which passes through the walls of the combustion chamber and is released outside. Therefore, the exhaust emission characteristics and wall heat loss are affected if soot formation during combustion differs depending on the aromatic content of the fuel oil. This study developed an analytical method that combines the temporal and spatial distributions of C2 and OH radicals (these species contribute to soot formation and oxidation) to evaluate the emission and wall heat loss characteristics of different aromatics in fuel oils via combustion and heat flux analysis. The method was applied to test fuels containing different aromatic contents. Two test fuels containing 60 vol% each of toluene (monocyclic) and 1-methylnaphthalene (bicyclic) were evaluated in a rapid compression machine with a 100 mm wall-to-wall distance combustion chamber. The results suggested that the differences in soot emissions were observed because of differences in aromatics, and no differences in the wall heat flux were observed. The distributions of C2 and OH radical luminescence intensities between the walls were examined, and the differences in soot production were attributed to differences in the C2 radical production upstream of the flame in the region of low air entrainment. The lack of difference in the heat flux between the test fuels can be attributed to the the differences in the C2 and OH luminescence intensities, which are related to the heat release rate and heat flux, being almost nonexistent near the walls.

A full-scale CFD model of scavenge air inlet temperature on two-stroke marine diesel engine combustion and exhaust emission characteristics

Most ships in the maritime transport sector are equipped with large two-stroke marine diesel engines in their propulsion systems. Therefore, ensuring stable and long-term operation of these engines is crucial to maintaining freight transportation. The design of the ship's machinery, particularly the diesel engine, is a crucial step in achieving this goal. Computational Fluid Dynamics (CFD) tools can be used to achieve this goal. This article presents a full-scale CFD study on the effect of different scavenge air inlet temperatures (300, 312, 330 and 340 K) on the combustion process and generation of exhaust emissions in a two-stroke marine diesel engine using ANSYS Forte software. Regarding the cylinder pressure, the presented model agrees well with experimental data. The maximum cylinder pressure decreases as the scavenge air inlet temperature increases, whereas the maximum cylinder temperature increases as the scavenge air inlet temperature increases. The maximum NOX, CO and UHC emission values are calculated to be 2256.5, 20375.8 and 3743.9 ppm, respectively, at a scavenge air inlet temperature of 340 K. Due to the higher combustion temperature caused by the increasing scavenge air inlet temperature, it is observed that the exhaust emission levels increase.

Exhaust emission and performance characteristics of coated CI engine fueled with hackberry biodiesel-diesel dual-fuel

Exhaust emission and performance characteristics of coated CI engine fueled with hackberry biodiesel-diesel dual-fuel

Computational fluid dynamic analysis of the effect of inlet valve closing timing on common rail diesel engines fueled with butanol–diesel blends

The inlet valve closing (IVC) timing plays a crucial role in engine combustion, which impacts engine performance and emissions. This study attempts to measure the potential to use n-butanol (Bu) and its blends with the neat diesel in a common rail direct injection (CRDI) engine. The computational fluid dynamics (CFD) simulation is carried out to estimate the performance, combustion, and exhaust emission characteristics of n-butanol–diesel blends (0%–30% by volume) for variable valve timings. An experimental study is carried out using standard valve timing and blends to validate the CFD model (ESE AVL FIRE). After validation, the CFD model is employed to study the effect of variable valve timings for different n-butanol–diesel blends. Extended coherent flame model-3 zone (ECFM-3Z) is implemented to conduct combustion analysis, and the kappa–zeta–f (k–ζ–f) model is employed for turbulence modeling. The inlet valve closing (IVC) time is varied (advanced and retarded) from standard conditions, and optimized valve timing is obtained. Advancing IVC time leads to lower cylinder pressure during compression due to reduced trapped air mass. The brake thermal efficiency (BTE) is increased by 4.5%, 6%, and 8% for Bu10, Bu20, and Bu30, respectively, compared to Bu0. Based on BTE, optimum injection timings are obtained at 12° before the top dead center (BTDC) for Bu0 and 15° BTDC for Bu10, Bu20, and Bu30. Nitrogen oxide (NOx) emissions increase due to complete combustion. Due to IVC timing, further carbon monoxide and soot formation decreased with blends and had an insignificant effect.

Modelling and experimental analysis of Aero-Engine performance and exhaust emission characteristics Fueled with green fuel blends

This study aims to assess the impact of using green fuel in place of biodiesel on the performance and exhaust emissions of air-breathing engines. GasTurb 13 is utilized to forecast the engine’s performance (kingTech 180 k turbojet engine). Catalytic deoxygenation of vegetable oils produces green diesel, offering an alternative to biodiesel. Physiochemical properties of GD blends (PME30GD20, PME20GD30, PME10GD10) were analyzed, and GasTurb-13 software predicted engine performance and emissions, validated with experimental data. The results show that GD10PME10 exhibited higher density (767.6 g/m3) than pure green fuel, while viscosity dropped by 53.85 % compared to PME. GD outperformed Jet-A1 by 0.74 % in heating value, with GD10PME10 having the highest at 42.63 MJ/kg. Engine performance measures included thrust, mass fuel flow, thrust-specific fuel consumption, and exhaust gas temperature. GD10PME10 showed a 12.5 % thrust increase and the lowest TSFC (95 g/kN.s) at 80,000 RPM compared to Jet-A1. GD20PME30 achieved the lowest EGT (550 °C) at the same RPM. Regarding emissions, GD20PME30 emitted the lowest CO (100,000 RPM, 150 ppm) and 0.5 % less CO2 (90,000 RPM) than Jet-A1. GD10PME10 produced the lowest NOx (12.5 ppm) at maximum speed, while Jet-A1 emitted the least NOx (7.5 ppm) at 120 k RPM. Overall, the data suggested that green fuel might increase the physiochemical properties of biodiesel blends, hence improving the fuel’s capacity to burn more effectively in aero-engines.

An investigation on the H2O, unburned H2 and NO emission characteristics from a direct injection hydrogen engine

Hydrogen engines show great potential as a power source with good combustion performance, zero carbon emissions, and diverse sources. However, the exhaust emission characteristics with high water vapor (H2O) content have not yet been clarified. This study presents the exhaust emissions of a heavy-duty direct-injection hydrogen engine under various operational parameters, with a focus on the H2O content. The results reveal important exhaust emissions characteristics of the hydrogen engine, including lower exhaust temperature (200 °C–400 °C), higher unburned H2 emissions (up to 17100 ppm), less nitrogen oxide (NO) generation (<1000 ppm), and higher H2O content (6%–40%). Additionally, unburned H2 rises, and NO and H2O decrease as the excess air ratio (λ) increases. When λ is greater than 3, NO levels fall sharply to below 100 ppm. Optimal emissions performance is achieved with a 5 °CA BTDC ignition timing where low levels of H2, H2O, and NO are maintained. Increasing hydrogen injection pressure decreases H2 but raises exhaust temperature, H2O, and NO emissions. Excessively delaying hydrogen injection timing adversely affects the concentration gradient in the cylinder, increasing unburned H2 emissions. The best emissions performance is observed at a hydrogen injection timing of 110 °CA BTDC.

Effects of dynamic injection pressures on spray, combustion, and exhaust emission characteristics in a CRDI diesel engine with naval vessel fuel

Effects of dynamic injection pressures on spray, combustion, and exhaust emission characteristics in a CRDI diesel engine with naval vessel fuel

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.

A machine learning-response surface optimization approach to enhance the performance of diesel engine using novel blends of Aloe vera biodiesel with MWCNT nanoparticles and hydrogen

This study aims to optimize the performance and exhaust emission characteristics of a dual-fuel diesel engine using wastewater-derived oxyhydrogen and nanoparticle-dispersed biodiesel/diesel blends. A Box Behnken Design (BBD) with L46 orthogonal arrays is employed to experiment with five factors and three levels of parameters: engine load, compression ratio, blend ratio, nanoparticle concentration, and oxyhydrogen (HHO) flow rate. In addition, six different machine learning algorithms (DTR, ABR, ETR, GBR, LGBM, and XGBR) are used to develop a prognostic model based on the acquired experimental data. These models estimate key performance indicators such as BTE, BSFC, CO, HC, and NOx. Based on the evaluation of performance indicators, including R2 (0.9729–0.9991), RMSE (0.0021–4.5765), MAE (0.0014–3.0015), and MAPE (2.37–4.83), the XGBR model demonstrates the most accurate predictions. Furthermore, the RSM-based desirability approach evaluates the trade-off between performance and emissions, thereby identifying the optimal engine operating condition. This condition includes a load of 7.17 kg, a compression ratio of 18:1, a blend ratio of 10 %, a nanoparticle concentration of 143 ppm, and an HHO flow rate of 5.57 L/min. The findings from the RSM analysis are validated through experimental investigation, demonstrating an error margin of 7 %. Overall, the introduction of oxyhydrogen improves combustion in a nanoparticle-dispersed biodiesel-diesel blend-powered diesel engine, resulting in increased engine performance and reduced carbon-based emissions, except for nitrogen oxide emissions.

Enhancement of Efficiency and Mitigation of Pollutan Emissions in a Compression Ignition Engine by the Utilization of Rice Bran Oil as Green Fuel

The current investigation involved the implementation of a research experiment aimed at assessing the operational and emission attributes of a compression ignition direct injection engine comprising a single cylinder. The engine was fuelled with rice bran oil (RBO), and its performance was analysed under different engine loads. The performance metrics that were analysed included the brake specific fuel consumption BSFC), brake thermal efficiency (BTE), exhaust gas temperature (EGT), and cylinder pressure. The exhaust emission parameters that were investigated include carbon monoxide (CO), carbon dioxide (CO2), hydrocarbons (HC), and oxide of nitrogen (NOX). The study compares the results obtained from an experimental investigation involving different variants of rice bran oil (RBO50, RBO75, RBO100) with those obtained from a diesel engine (RBO00). The lowest BSFC obtained for RBO100 is around 0.29 kg/kWh at maximum load conditions (75 %), while the highest obtained for RBO00 is 0.33 kg/kWh. For all operations of diesel and RBO blends, it was discovered experimentally that the BSFC increases until 25 % of engine load and then starts to decline as the engine load is raised. At normal engine load circumstances, RBO75 has the highest thermal efficiency, while RBO00 has the lowest. The high EGT reading of RBO50 blends was due to the high calorific value (CV) of the fuel blends, which produced more heat per unit mass than RBO75 and RBO100. RBO75 achieved the highest cylinder pressure under both half and full load scenarios. RBO00 (pure diesel) achieved the lowest cylinder pressure under both half and full load scenarios. RBO outscored diesel in terms of efficiency of engine. The exhaust emission characteristics that were assessed included NOX, CO2, HC, and CO. The experimental outcomes of the study using rice bran oil-based fuels, specifically RBO50, RBO75, and RBO100, are being contrasted with those of diesel fuel (RBO00). The findings indicate that emissions of CO, CO2, HC, and NOX are lower when using RBO75 and RBO100 compared to diesel fuel. Furthermore, an analysis was conducted to determine the HC emissions of both RBO75 and RBO100 fuels at two distinct engine speeds, specifically 3500 rpm and 2000 rpm. The HC emission level for RBO75 was observed to be at its peak of 211 ppm when the engine speed reached 3500 rpm. The RBO50 fuel exhibits lower levels of CO emissions, measuring at 1.2% (3500 rpm) and 0.32% (2000 rpm). Similarly, CO2 emissions are also reduced with RBO50, measuring at 8.3% (3500 rpm) and 6.9% (2000 rpm). These exhaust emission reductions are observed when comparing RBO50 to diesel (RBO00) and other fuel mixtures, under a 75% load condition. Elevated levels of NOX emissions were detected in diesel fuel (RBO00) at concentrations of 499 ppm (3500 rpm) and 599 ppm (2000 rpm). In comparison to other fuels such as RBO50, RBO75, and RBO100, these higher NOX emissions were noted. In summary, the emission properties of RBO were shown to be superior to those of diesel fuel. The optimal blend for emissions reduction, including CO2, CO, NOX, and HC, was determined to be RBO50.

Real-Time LNG Buses Emissions Prediction Based on a Temporal Fusion Trans-Formers Model

Emissions from transportation are one of the key factors preventing the achievement of carbon peaking and carbon neutrality by 2050, with particular attention to emissions from buses. Specifically, few research has been conducted on the exhaust emissions characteristics of liquified natural gas (LNG) buses under different driving scenarios. This study proposed a framework for predicting exhaust emissions of LNG buses based on the portable emission measurement system and GPS collaborative perception data. Firstly, the emission distribution characteristics of CO2, CO, HC, and NOx from LNG buses in real-world driving were analyzed by visualization methods. Then, the real-time exhaust emissions of LNG buses were predicted based on the temporal fusion transformers model for both urban and suburban sections of Zhenjiang City, and the model validity was verified. The current and past 10 s driving states were used for predicting the emission rate of LNG buses. The results showed that the proposed model outperforms other advanced algorithms in real-time exhaust emissions prediction of LNG buses, with an average R2 value higher than 0.94 and an average MAPE reduction of 14.19%. The error assessment revealed that the emission values and average emission rates are higher when driving in the urban section compared to the suburban section. Among the influencing factors, traffic conditions have the most significant impacts on the exhaust emissions of LNG buses, followed by road conditions and driving states, with relative feature importance of 48.9, 34.8, and 16.3%, respectively. Additionally, the current and past 10 s driving states also significantly influenced real-time predictions. This study provides an essential theoretical reference for reducing exhaust emissions for city buses.

Effects of diesel injection timing and methanol substitution ratio on combustion and exhaust emission characteristics of a dual fuel compression ignition engine

Effects of diesel injection timing and methanol substitution ratio on combustion and exhaust emission characteristics of a dual fuel compression ignition engine

Research on the driving characteristics of motor vehicles in high-altitude areas for the analysis of exhaust emission characteristics

Research on the driving characteristics of motor vehicles at different altitudes in plateau regions and road emission intensity can provide technical support for energy conservation and emission reduction policies in plateau areas. This paper selects gasoline and diesel vehicles for on-board testing on typical road sections in plateau regions to study the overall driving characteristics of motor vehicles and the driving characteristics at different altitude intervals in plateau areas. The results show that with the increase in altitude, the driving conditions gradually concentrate towards ’high speed, low acceleration.’ The relevant conclusions can further study and analyze the distribution patterns of pollutants in motor vehicle exhaust emissions and road emission intensity.

Investigation of Exhaust Emission Characteristics of Gasoline Fuelled Motorcycles Using Post-Combustor

Exhaust emissions from internal combustion engines are due to incomplete combustion of fuel in the combustion chamber. This incomplete combustion results in a significant increase in the amount of Carbon Mono-oxide, Un-burned Hydrocarbons, and Oxides of Nitrogen in the exhaust stream. This study proposes a new approach to minimize the amount of pollutant emitted by internal combustion engines using a post-Combustor which consist of heating elements known as Glow-plugs that degrade Carbon mono-oxide, Hydrocarbons, and Oxides of Nitrogen using a high temperature that is up to 1600˚C. This Post-Combustor can be retrofitted in any existing vehicle's exhaust line without any alterations. Moreover, it is designed such that there is no increase in fuel consumption; it only utilizes electrical energy from the vehicle's electrical system.

Retracted: Performance and Exhaust Emission Characteristics of C.I Engine Using Biofuels and Its Diesel Blend with Nano-Additives

Retracted: Performance and Exhaust Emission Characteristics of C.I Engine Using Biofuels and Its Diesel Blend with Nano-Additives

A Review of Properties, Engine Performance, Emission Characteristics and Material Compatibility Biodiesel From Waste Cooking Oil (WCO)

Biodiesel is one of the renewable energy sources, non-fossil. The chosen feedstock should ideally be low-cost. Using waste cooking oil can reduce synthetic biodiesel's price by up to 70%. However, biodiesel has the advantage of lower heating value and higher density, causing increased fuel consumption and NOx emissions. Biodiesel has physicochemical properties such as a more significant cetane number than fossil diesel, a high flash point, and the absence of sulfur. This study identifies the potential availability of WCO as biodiesel and summarizes recent studies on the physiochemical properties of WCO biodiesel. This study also aims to clarify the use of WCO biodiesel on engine performance and exhaust emission characteristics (H.C., CO, CO2, NOx) when this biodiesel is used. Engine type and biodiesel ratio were identified for all articles. This study also discusses the effect of adding nanoparticles on engine performance and exhaust emissions in WCO biodiesel. This study also clarifies material compatibility (corrosion, wear, and friction). The corrosion rate in various types of materials and corrosion testing methods. Finally, this paper presents the opportunity for WCO biodiesel to be very feasible to reduce fossil diesel use.

Investigation of the Impact of Castor Biofuel on the Performance and Emissions of Diesel Engines

Fossil fuel is a non-renewable fuel, and with the development of modern industry and agriculture, the storage capacity of fossil fuels is constantly decreasing. In this study, a systematic study and analysis were conducted on the combustion characteristics, engine performance, and exhaust emission characteristics of castor biodiesel–diesel blends and pure diesel fuel in different proportions at different speeds of a single-cylinder four-stroke diesel engine under constant load. The castor biodiesel required for the experiment is generated through an ester exchange reaction and mixed with diesel in proportion to produce biodiesel–diesel blends. The experimental results show that as an oxygenated fuel with a higher cetane number, the CO, HC, and smoke emissions of diesel and B80 blend fuel at 1800 rpm were reduced by 16.9%, 31.6%, and 68%, respectively. On the contrary, the NOx and CO2 emissions increased by 17.3% and 34.6% compared to diesel at 1800 rpm. In addition, due to its high viscosity and low calorific value, the brake thermal efficiency and brake-specific fuel consumption of the biodiesel–diesel blends are slightly lower than those of diesel, but the biodiesel–diesel blends exhibit lower exhaust gas temperatures. Comparing B80 and diesel fuel at 1800 rpm, the BSFC of diesel at 1800 rpm is 3.12 kg/W·h, whereas for B80 blended fuel, it increases to 4.2 kg/W·h, and BTE decreases from 25.39% to 21.33%. On the contrary, B60 blended fuel exhibits a lower exhaust emission temperature, displaying 452 °C at 1800 rpm. Based on the experimental results, it can be concluded that castor biodiesel is a very promising clean alternative fuel with low waste emissions and good engine performance.

Development of combustion control map for flex fuel operation in methanol powered direct injection SI engine

The current study proposes a model-based calibration strategy for developing an optimum combustion control map in furtherance of flex-fuel operation with methanol-gasoline blends. Furthermore, a model is developed through the response surface methodology (RSM) for the engine parameters and responses based on the experimental results. In addition, a multi-objective optimization is enacted that relies on a desirability approach keeping equal attention to engine performance and exhaust emission characteristics. The established RSM model exhibits a reliable prediction ability across the operating realms of the engine. Thereby, it has been explored the tendency of parameter calibration and its effects on the engine responses for gasoline and methanol-gasoline blends are studied. From the optimally calibrated map, the test fuel of M30 shows the highest value of brake thermal efficiency (BTE) of 30.76 % and the lowest level of brake specific fuel consumption (BSFC) is recorded for M0 about 147 g/kWh. Besides, the maximal value of 1.70 %vol, 13.96 %vol, 268 ppm, and 535 ppm is observed in the engine exhaust for carbon monoxide (CO), carbon dioxide (CO2), hydrocarbon (HC), and nitrogen oxides (NOx) respectively despite of fuel used. Moreover, the validation results assure and reveal identical outcomes with predicted values within the allowable errors.