Exhaust Gas Recirculation Technique Research Articles

Toward improving efficiency and mitigating emissions in a natural gas/diesel direct injection dual fuel engine using EGR

As emissions regulations become more and more stringent and conventional fuel sources rarefaction, new alternatives are emerging to address this situation. Dual fuel engines are among the promising solutions, offering both ecological and economic advantages. However, these engines often confront constraints linked to high levels of unburnt hydrocarbons (HC) at low loads and NOx emissions at high loads. To overcome these problems and guarantee high-efficiency overall operating loads, exhaust gas recirculation (EGR) is a potential solution. In the present experimental study, appropriate modifications have been carried out to a single-cylinder diesel engine to ensure dual fuel operation with EGR. Natural gas and diesel are used as the primary and pilot fuel, respectively. At low load operations, the EGR rate is increased up to 35% until the reduction of unburnt hydrocarbons. However, at high loads, the EGR rate is carefully adjusted, as the combustion efficiency easily deteriorates due to oxygen amount lack in the combustion chamber. Also, minimizing NOx emissions is prioritized in all load conditions while keeping thermal efficiency in sight. In addition, the variation in the amount of pilot fuel is studied for improving the combination of dual fuel engine operation with the EGR technique. This made it possible to determine the influence of load, EGR rate, and pilot fuel quantity on the engine in response to the triple challenges of reducing NOx and HC and improving thermal efficiency. The results show that an adequate EGR rate of 30%, depending on the operating conditions, can reduce HC emissions by >25% while increasing thermal efficiency by around 20%. This result is accompanied by a significant reduction, over 90%, in NOx emissions.

Comparative analysis of Diesel, B50, and H50 fuels in a diesel engine employing air-fuel ratio and exhaust gas recirculation

Past research has mostly concentrated on the utilization of hydrogen or biodiesel in various proportions when blended with diesel fuel. Despite considerable research conducted on the utilization of fuel blends consisting of hydrogen and biodiesel. Currently, there is a lack of research that has conducted a comparative analysis regarding the impact of air-fuel ratio on the performance of diesel fuel blended with Hydrogen and FAME. This research article examines three fuel blends to determine four critical diesel engine parameters (BTE, Brake Torque, NOx concentration, and BMEP) at five distinct air-fuel ratios spanning from 14 to 65. The present study aims to enhance the comprehension of the intricate characteristics of air-fuel mixtures, specifically rich, stoichiometric, and lean, by conducting an extensive analysis. Additionally, the investigation focuses on the impact of the exhaust gas recirculation technique on the NOx concentration. This article presents a mono-cylinder diesel engine model developed in the Ricardo wave program, simulated in three cases: I) Diesel only, II) B50(Blend of 50 % Diesel and 50 % FAME), and III) H50(Blend of 50 % Diesel and 50 % Hydrogen) at a compression ratio 21 with an rpm ranging from 500 to 2500.Fair agreement with peak results deviating in a few percent revealed that H50 significantly enhances brake thermal efficiency (BTE) measured to Diesel and B50, with improvements of up to 5.6 % and 5 %, respectively. When Hydrogen is mixed with Diesel, the combustion process quickens and becomes more complete, and ultimately, an improved combustion quality is achieved. H50 generates 13 % and 12 % higher levels of NOx in comparison to Diesel and B50, respectively. Increased engine speed triggers the in-cylinder temperature to rise, promoting NOx generation. The heat release rate is a significant parameter for assessing combustion efficiency. Diesel releases more heat than B50 at a particular crank angle. However, from 15-64° CA, B50 keeps generating more heat than Diesel. Thereby, B50 releases more heat than the Diesel overall. The Brake torque and BMEP decrease with the increase in AFR for each case. In conclusion, H50 and B50 generate higher BTE than Diesel. Meanwhile, this comes at the cost of a rise in NOx concentration. When the exhaust gas recirculation is applied at 25 %, the NOx concentration is reduced drastically, and it is further deduced that the rate of change of EGR is inversely proportional to the NOx concentration.

Comprehensive Analysis of Compression Ratio, Exhaust Gas Recirculation, and Pilot Fuel Injection in a Diesel Engine Fuelled with Tamarind Biodiesel

The global automotive industry is facing significant challenges, including dwindling fossil fuel reserves, rising crude oil prices, and increasingly strict emission regulations. To address these concerns, this study investigates the impact of the compression ratio (CR) and exhaust gas recirculation (EGR) on the performance and emissions of a common rail direct injection (CRDI) diesel engine fuelled with a 20% blend of tamarind seed methyl ester (TSME 20) biodiesel. The study employed an open-type electronic control unit to implement pilot fuel injection at a rate of 30%, 23° before the top dead centre (TDC), and at a higher pressure of 600 bar. Three CRs (16:1, 18:1, 20:1) and two types of EGR (hot and cold EGR at 10%) were evaluated. Diesel fuel at CR 18 was used as a baseline for comparison. The experimental procedure involved conducting tests with TSME 20 at CR 16, 18, and 20. Subsequently, TSME 20 at CR 20 + Hot EGR 10% and TSME 20 at CR 20 + Cold EGR 10% were examined. The results showed that TSME 20 operated at a higher CR (CR 20) exhibited improved diesel engine performance and significant reductions in harmful exhaust emissions. Additionally, cold EGR at 10% was more effective in reducing CO, CO2, and NOx emissions from TSME 20 than hot EGR. The findings of this study provide valuable insights into optimizing diesel engine operation to achieve a balance between performance enhancement and emission reduction through tamarind seed biodiesel blends and different EGR techniques. The implementation of these strategies holds considerable potential in addressing the automotive industry’s challenges, including ecological considerations and fuel price fluctuations.

Investigating the Effects of Eichhornia Crassipes Biodiesel and Liquefied Petroleum Gas on the Performance and Emissions of a Dual-Fuel Engine

This study considers the effect of Eichhornia Crassipes Biodiesel (ECB) blends on the performances, combustion, and emission characteristics of a direct injection compression ignition engine operated in a dual-fuel mode (DFM) and equipped with an Exhaust gas recirculation technique (EGR). In particular, a single-cylinder, four-stroke, water-cooled diesel engine was utilized and four modes of fuel operation were considered: mode I, the engine operated with an ordinary diesel fuel; mode II, the engine operated with the addition of 2.4 L/min of liquefied petroleum gas (LPG) and 20% EGR; mode III, 20% ECB with 2.4 L/min LPG and 20% EGR; mode IV, 40% ECB with 2.4 L/min LPG and 20% EGR. The operation conditions were constant engine speed (1500 rpm), variation of load (25%, 50%, 75%, and 100%), full load, with a compression ratio of 18, and a time injection of 23° BTDC (Before top died center). With regard to engine emissions, carbon dioxide (CO₂), carbon monoxide (CO), hydrocarbons (UHC), and nitrogen oxide (NO_X) were measured using a gas analyzer. The smoke opacity was measured using an OPABOX smoke meter. By comparing the results related to the different modes with mode I at full load, the BTE (Brake thermal efficiency) increased by 20.17%, 11.45%, and 12.66% with modes II, III, and IV, respectively. In comparison to the results for mode II, the BTE decreased due to the combustion of ECB blends by 7.26% and 6.24% for mode III and mode IV, respectively, at full load. In comparison to mode II, the Brake specific energy consumption (BSEC) increased with the ECB substitution. With ECB blends, there is a noticeable decrease in the CO, CO_2, and UHC emissions at a partial load. Furthermore, the 20% ECB has no effect on CO emissions at full load. For modes II and IV, the CO₂ increased by 33.33% and 19%, respectively, while the UHC emissions were reduced by 14.49% for mode III and 26.08% for mode IV. The smoke of mode III was lower by 7.21%, but for mode IV, it was higher by 12.37%. In addition, with mode III and mode IV, the NO_x emissions increased by 30.50% and 18.80%, respectively.

On the impact of turbocharger thermo-mechanical limitations on new generation gasoline engines

Among other advances in spark ignited internal combustion engines’ field, the variable geometry turbine (VGT) is being analysed to achieve further CO2 reduction objectives. This paper analyses the potential implications of replacing nowadays standard, the waste-gate (WG) technology, with VGT.To do so, after developing a robust and validated model, this work proposes a methodology to optimize the variable valve timing (VVT), at full load working conditions, in a new generation spark ignited (SI) engine, coupled to a VGT prototype. The optimization methodology accounts for the different thermo-mechanical limits of such technology compared to the reference WG turbocharger, particularly in terms of the turbine inlet temperature (T3). Torque differences show a systematic improvement by using a VGT, reaching approximately 22 Nm of improvement and about 17 g/kWh, although the difference in torque is smaller after 3500 rpm due to the more restrictive T3 limit imposed.As well, at partial loads, the same procedure is developed, but targeting the optimization of the engine efficiency. At partial loads, when no exhaust gas recirculation technique is applied, few advantages are identified. However, with exhaust gasses recirculation (EGR) technique, improvements reach 3 g/kWh and permit extending the desired EGR rate towards the lower speeds.

Numerical investigation on hydrogen-diesel dual-fuel engine improvements by oxygen enrichment

Hydrogen-diesel dual fuel (HDDF) technology is one approach available to improve the performance and reduce carbon-based emissions of compression ignition (CI) engines. Unfortunately, when operated at partial and low loads, HDDF engine configurations suffer from poor fuel utilization, combustion efficiency and ignition delay. As partial load application is increasingly important to performance of hybrid power systems, this paper explores the use of oxygen enrichment to improve HDDF performance outside of conventional load applications.In this paper, a numerical model was first developed and validated for HDDF combustion using experimental data. This model was subsequently applied to study the influences of oxygen enrichment on engine performance and emission characteristics. Furthermore, the Exhaust Gas Recirculation (EGR) was implemented as a secondary control for NOx emission reduction. For this configuration the results showed that oxygen enrichment (between 21% and 27% by volume) into the intake manifold led to an improved combustion efficiency and reduced carbon-based emissions. The brake thermal efficiency (BTE) increased by 1.6% and the brake specific energy consumption decreased by 4%. Across the emissions spectrum, soot emission reduced by 72%, whereas NOx emission increased by 63% without using the EGR technique. By combining oxygen enrichment and EGR strategies, a considerable reduction of 79% in NOx and an increase of 2.6% in BTE was observed for the oxygen concentration of 27% and EGR rate of 24% compared to a conventional HDDF operation with 45% HES ratio.

Emissions Reduction in an Automotive Compression Ignition Engine using Hydrogen and Exhaust Gas Recirculation

ABSTRACT This paper deals with the experimental investigation of an automotive compression ignition (CI) engine under dual fuel mode (hydrogen-diesel) with exhaust gas recirculation (EGR). The engine was operated under different speeds at 16 Nm (maximum torque). Smoke, CO, and HC emissions decreased drastically with hydrogen. However, maximum hydrogen energy share (HES) is limited to 56% at 2000 rpm and 63% at 2400 rpm due to combustion with knock and NOx emission raised drastically. EGR technique was used to enhance the knock limited HES and reduce NOx emission. The maximum HES without knock is extended to 68% with 20% EGR (2000 rpm). NOx emission decreased to near-zero level. Brake thermal efficiency increased. CO and HC emissions decreased significantly. However, smoke increased but still lower than base diesel. The combined effect of hydrogen and EGR could reduce the emissions, energy efficiency improvement, and extend the maximum HES limit.

Numerical investigation of combustion characteristics of a single-cylinder linear engine fueled by natural gas under the influence of exhaust gas recirculation

The effect of applying the exhaust gas recirculation technique on the performance of a free-piston engine, including the resulting emissions, is introduced and assessed in this study. The simulation process has been performed over a single-cylinder, two-stroke free-piston engine that uses a homogeneous charge compression ignition. Two main sub-models that work implicitly to simulate the engine performance and emissions in an iterative simulation procedure using MATLAB® and Cantera toolbox. It was found that recycling a small percentage of the exhaust gases (∼10%) has a significant effect on reducing the engine emissions, like the NO x levels. Four different levels of EGR were applied in the simulations at , , and . Raising the percentage of the recirculated gases beyond a specific threshold will encounter a negative outcome by increasing the emissions of other particles, such as the UHC and CO. Moreover, it can lower the oxygen (O2) concentrations causing an incomplete fuel–air burning which reduces the combustion efficiency. The recirculation of 30% of the exhaust gases was aggressively able to reduce about 14 g/kWh of NO x at the ignition time compared to no recirculation, and about 8 g/kWh at the steady state.

Influence of hexanol/hydrogen additives with diesel fuel from CRDI diesel engine with exhaust gas recirculation technique: A special focus on performance, combustion, gaseous and emission species

Emission and combustion parameters of common rail direct injection combustion engine with different proportions of exhaust gas recirculation rate and 1-hexanol blends with hydrogen on performance are the main motive of this research. To lessen the dependency on diesel fuel and reduce harmful emissions, 1-hexanol is used, as it has better fuel properties than small-carbon-chain alcohol, and it can be blended with diesel. In common rail direct injection combustion engine, a research was conducted, in which fuel blends (1-hexanol-diesel) were variant, i.e., (10%, 20%, 30%) by volume whereas engine speed was fixed at 1500 rpm by varying the load at 25% step from 25 to 100%. Blends were examined with various exhaust gas recirculation rates (10% and 20%) to see what impact they have on engine properties. It was observed that the higher the proportion of 1-Hexanol, the lower the engine performance. The research revealed that for the blend D70H30/H2, around 8.24% rise in brake specific fuel consumption, slight rise in hydrocarbon, 2.80% reduction in brake thermal efficiency, and 16.70% reduction in nitrogen oxides (NOx) emission. With 1-hexanol-diesel-hydrogen blends, the engine is noted to function effortlessly, so as a substitute to the diesel up to 30% of the 1-hexanol can be used while increasing the total cost of implementation.

Exhaust Gas Recirculation on a Nano-Coated Combustion Chamber of a Diesel Engine Fueled with Waste Plastic Oil

Managing waste plastic is becoming a severe challenge. The industry and researchers have been looking at various opportunities in line with circular economy principles for effective plastic waste management. In that context, plastic waste valorization to oil as a substitute to fossil fuel has gained recent attention. In the literature, there exist few studies showing the use of oil derived from waste plastics in blends with other conventional fuels in compression ignition (CI) engines; however, studies on CI engines that use 100% waste-derived fuels are limited. Additionally, the exhaust gas recirculation (EGR) concepts and the use of nano-coated chambers (like pistons, valves and cylinders heads) have been gaining interest purely from the engine performance enhancement perspective in recent years. Therefore, this study investigates engine performance by combining exhaust gas from the EGR technique and waste plastic oil (WPO) as inputs, followed by thermal coatings in the CI engine chambers for performance enhancement. The experimental setup of the engine is developed, and the engine’s piston, valve and cylinder heads are coated with Al2O3-SiO4 material. The CI engine’s energy, emission, and combustion characteristics are tested, followed by a scenario analysis compared with diesel-only fuel. The tested scenarios include a WPO + Al2O3-SiO4, WPO + Al2O3-SiO4 + 10% EGR, and WPO + Al2O3-SiO4 + 20% EGR. The results show that the piston crown’s thermal coating increased the combustion performance. Significant impacts on the carbon monoxide, hydrocarbons, and smoke characteristics are observed for different %EGR rates. The results also showed that the cooled EGR engine has decreased nitric oxide emissions. Overall, the results show that WPO combined with exhaust gas could be a potential fuel for future CI engines.

Performance, Combustion, and Emission Characteristics of a Common Rail Direct Injection Diesel Engine Fueled by Diesel/n-Amyl Alcohol Blends With Exhaust Gas Recirculation Technique

AbstractBiofuels are considered as one of the best viable and inexhaustible alternatives to conventional diesel fuel. Alcohols have become very important and popular in the present scenario due to their peculiar fuel properties and production nature. This study examines the effect of n-amyl alcohol and exhaust gas recirculation of 10% and 20% on various engine characteristics of common rail direct injection (CRDI) compression ignition engine. The proportion of n-amyl alcohol varies from 5% to 25% in 5% step (by volume). The obtained results show that diesel/n-amyl alcohol blends decrease the mean gas temperature and cylinder pressure, which is 1.88% and 4.25% less at 75% load for n-amyl alcohol (25%) with conventional diesel fuel. The duration of combustion has shown a hike of 4.66 °CA for 25% n-amyl alcohol (at 75% load) compared to conventional diesel fuel. However, the cumulative heat release rate improved by 12.95% higher for 25% n-amyl alcohol at 75% load due to the extended delay in ignition. While n-amyl alcohol was used, the emission of nitrogen oxide emissions decreased considerably. However, the hydrocarbon (HC) (7–9%) and carbon monoxide (CO) (6–8%) emissions are increased due to inferior fuel properties like high latent heat evaporation of n-amyl alcohol. Compared with other blends, n-amyl alcohol (5%) produced results comparable to conventional diesel fuel, which is 3.6% higher in BSFC, 2.37% higher BTE, and 33.33% higher CO emissions 18.18% more in HC emission, and 17.55% less NOx emission. Without further modification, we can use 25% n-amyl alcohol in the combustion ignition engines. From this evidence, we can summarize that n-amyl alcohol is a biofuel that is both renewable and sustainable, and also it considerably reduces harmful nitrogen oxide emissions. The performance, if needed, can be improved by changing the parameters of the engine.

Mixture temperature-controlled combustion: A revolutionary concept for ultra-low NOX emission

Mixture Temperature-Controlled (MTC) combustion is a novel concept, offering 50% reduction in NOX emission compared to V-shaped flames without a known compromise. The essence of this concept is the central cold air injection, which is also the atomizing medium of the plain-jet airblast atomizer presently to delay fuel–air mixture ignition. Hence, the flame root is not anchored to the fuel nozzle or burner lip, facilitating distributed combustion through a homogeneous temperature field, ultimately leading to reduced NOX emission. The flame was stable up to an equivalence ratio of 0.57, which was followed by blowout as the lean flammability limit was approached. Lean combustion also means reduced flame propagation speed, being another key feature to keep the flame lifted and facilitating homogeneous mixture formation. It was observed that distributed combustion was easier to achieve under leaner conditions. Unlike flameless combustion or exhaust gas recirculation techniques, such as MILD combustion, the oxidizer can be ambient air, offering robust realization in practical applications. The distributed flame is characterized by low flame luminosity and noise. Its acoustic spectrum contains geometry-related components principally. Hence, it is hypothesized that this concept also has a lower tendency to thermoacoustic instabilities than V-shaped flames.

Evaluation of animal fat based biodiesel blends and effects of exhaust gas recirculation on the suitable blend in single cylinder four stroke diesel engine

ABSTRACT An experimental study is carried out to evaluate the effects of animal fat biodiesel blends with diesel and exhaust gas recirculation (EGR) for the suitable biodiesel blend selected on performance, emission, and combustion characteristics in single cylinder four-stroke diesel engine. Animal fat biodiesel (AFB100) is prepared through the transesterification process. Diesel fuel is mixed with animal fat biodiesel and the animal fat-based biodiesel blends are prepared such as AFBB20, AFBB40, and AFBB60. Few important properties for the prepared blends are found and tabulated in table 1. In this investigation, AFBB20 yields better performance and emission characteristics compared to other tested biodiesel blends. Increasing NOx emissions is not good for the environment and creates health issues. To reduce the NOx emission for the selected blend AFBB20, the EGR technique is applied by 0%, 10%, 20%, and 30%, and investigates in the same engine. In the EGR investigation, lower brake specific fuel consumption and higher BTE are found in 10% EGR. Lowered CO and UHC emissions are found in EGR 10%. Compared to 0% EGR, drastic reduction in NOx emission is found by 16.5% and 17.5% reduced smoke emission is found in 10% EGR rate compared to AFBB20. Abbreviations: BSFC: Brake specific fuel consumption; BTE: Brake thermal efficiency; CO: carbon monoxide; UHC: unburned hydrocarbons; NOx: nitrogen oxides; EGT: Exhaust gas temperature; CP: Cylinder Pressure; HRR: Heat release rate; bTDC: Before top dead center; aTDC: after top dead center; ppm: parts per million; IC: internal combustion engine; CI: compression ignition; EGR: exhaust gas recirculation; DAQ: data acquisition system; PD 100: Petro diesel; AFBB: Animal fat biodiesel blends; AFB100: animal fat biodiesel; AFBB20 (PD 80% + AFB 20% by volume),; AFBB40 (PD 60% + AFB 40% by volume) AFBB60 (PD 40% + AFB 60% by volume)

Effect of fuel injection pressure and EGR techniques on various engine performance and emission characteristics on a CRDI diesel engine when run with linseed oil methyl ester

Nowadays, owing to the reduction in petroleum supplies due to the growing oil demand, the search for alternate fuels has intensified. However, as alternate fuel choice grows, checking whether alternative fuels are suitable for use in engines has become time-consuming and expensive. Therefore, the usage of Linseed oil methyl ester (linseed biodiesel) in the common rail direct injection (CRDI) diesel engine was optimized for a smaller number of trials in this research. Response surface methodology (RSM) was employed for optimization. Input variables were chosen for LOME content in the blend, fuel injection pressure (FIP), exhaust gas recirculation (EGR) rates, and engine load while output parameters were selected for like indicated power (IP), indicated thermal efficiency (η(I)), indicated mean effective pressure (IMEP), hydrocarbon (HC), and NOx (Oxide of Nitrogen).The model layout employed in the analysis is focused on the matrix of the CCRD (central composite rotating design). The optimal input variables configuration is estimated at 5.45% LOME blend, 57.77 MPa FIP, 6.50% EGR, and 6.909 kg engine load leading to better efficiency together with reduced emissions. The optimized output of the engine at this input configurations are as IP 4.878 kW, IMEP 0.5886 MPa, indicated thermal efficiency 48.36%, HC 23.43 ppm vol., and NOx 533.15 ppm vol. Testing and optimum output response results are measured at acceptable input parameters and are considered to be within an acceptable error range. The findings of this analysis have shown that RSM is an appropriate technique for optimizing CRDI diesel engines.

Experimental investigation of performance and emissions of CRDI diesel engine in dual fuel mode by hydrogen induction and diesel injection coupled with exhaust gas recirculation

IC engines are the main resources of power in our daily life particularly in transportation, agricultural sectors and power generation. However, faster depletion of petroleum resources and environmental issues raised because of abundant use of it and are the driving force behind the search for replacement of petroleum products with newer reliable alternate fuels. In this point of view, hydrogen is the most promising alternate fuels because of its cleaner combustion characteristics to resolve the earlier stated issues as being the best renewable energy resource. In the current research work, the supplementary fuel used is hydrogen which was injected inside the intake manifold by solenoid type of hydrogen injector whereas diesel is directly injected inside the engine cylinder. The prime intention of current work is to replace the diesel energy share with hydrogen energy in single cylinder CRDI equipped diesel engine and reduction of Oxides of Nitrogen emission which was resulted due to maximum hydrogen energy share during combustion at higher flow rate using exhaust gas recirculation technique. The experimentation was carried out on single-cylinder 4 S water cooled CRDI equipped engine. The effect of hydrogen addition with use of various flow rates of exhaust gas recirculated on engine performance along-with emission parameters were investigated at different loading conditions of engines. The hydrogen enriched dual fuel mode of operation together with exhaust gas recirculation technique resulted in improved performance as well as emissions factors of CRDI diesel engine in comparison with neat diesel except NOx which could be further reduced by cooled maximum mass flow rate of EGR which can be employed is suggested.

Effects of External Mixture Formation and EGR Technique on a Diesel-Fueled PCCI Engine

Limitations on exhaust emissions of diesel engines have become increasingly stringent due to increasing awareness of environmental protection. This challenges diesel engine manufacturers to find a new balance between engine performance and emissions. Advanced combustion modes for diesel engines, such as homogeneous charge compression ignition (HCCI) and premixed charge compression ignition (PCCI), which can simultaneously reduce exhaust emissions and substantially improve thermal efficiency, have drawn increasing attention. In order to allow enough time to prepare the homogeneous mixture, the external mixture formation technique was used to achieve PCCI combustion. A device known as diesel vaporizer was used to produce diesel vapors. Diesel vapors mix with air at intake port of an engine to form homogeneous charge before combustion starts. Exhaust gas recirculation technique was used to control early ignition of the premixed charge. It was observed from the experimentations that the use of external mixture formation technique with EGR in PCCI engine decreases the NOx emissions by 43.57% but increases HC and CO emissions due to low temperature combustion. The brake thermal efficiency obtained was just 1.9% less than the conventional CI engine.

Investigating the influence of oxygenated fuel on particulate size distribution and NOX control in a common-rail diesel engine at rated EGR levels

The effect of butanol-diesel blend (B20) and different rates of exhaust gas recirculation (EGR) on particulate matter (PM) characterisation and NOX emissions were investigated in this experimental work. The different rates of EGR (0%, 15% and 30%) and oxygenated fuel (B20) were used in this study. The brake thermal efficiency (BTE) of the engine increased under without used EGR technique compared to the presence of EGR during combustion process for B20 and diesel fuel. Further, higher BTE produced during the combustion of B20 than that produced from combustion of diesel for different rates of EGR. The BSFC slightly increased with B20 combustion compared to the diesel combustion. The cylinder pressure and ROHR improved with combustion of B20 under without using EFR. The results showed that PM reduced from the combustion of B20 more than to the diesel fuel for different rates of EGR. Besides, the average of particle diameter reduced from B20 combustion by 20, 22 and 25 nm compared to the diesel by 31, 37 and 43 nm for 0%, 15% and 30% of EGR, respectively. The soot particles generated from B20 combustion are lower than to the diesel fuel combustion for different rates of EGR. Lower level of NOX emissions can be achieved with using EGR (15% and 30%) than to the without EGR technique, this effect is more clearly with oxygenated fuel. It is indicated that the EGR dramatically increase the THC and CO emissions when exceeds the 30% with no obvious influence on NOX emissions.

Reduction of emissions in a biodiesel‐fueled compression ignition engine using exhaust gas recirculation and selective catalytic reduction techniques

AbstractThis paper analyzes the emissions of a single‐cylinder diesel engine fueled with biodiesel, using selective catalytic reduction (SCR) and exhaust gas recirculation (EGR) techniques. The aim of this paper is to compare both EGR and SCR techniques, which were studied under different brake powers. Grape seed biodiesel was used as a test fuel. Experiments were performed by both techniques at different loads and rates to find out the performance change in the engine and the change in the emission rates using both the techniques. Then the observations from both the techniques were compared, concluding that both the techniques show a sufficient reduction in NOx. Using the abovementioned techniques, a reduction in hydrocarbon (HC), carbon monoxide (CO), carbon dioxide (CO2), nitrogen oxides (NOx), and smoke was observed. The EGR technique is more suitable for low‐load engine vehicles, as it affects the efficiency of the engine with an increase in the fuel consumption, whereas the SCR technique is suitable for high‐load engines, which do not affect the efficiency of the engine with a decrease in the fuel consumption.

Effect of exhaust gas re-circulation on performance, emission and combustion characteristics of ethanol-fueled diesel engine

Ethanol, as a fuel for compression ignition (CI) engine, has some advantages over diesel fuel, and these include the reduction of soot, carbon monoxide (CO) and unburned hydrocarbon (HC) emissions. However, there are few concerns about ignition properties, and emissions (especially the particulate and NOx). For minimizing the emissions from the ethanol-fueled compression ignition (EFCI) engine, the exhaust gas recirculation (EGR) technique is proposed. In this paper, the EGR technique is used where some amount of the exhaust gas is drawn off from the exhaust system, cooled, and redirected back into the cylinders. The experimental setup of the ethanol-fueled diesel engine (EFDE) with EGR is developed. Using the setup, the performance, emission, and combustion characteristics of EFDE in different scenarios of EGR (ethanol + coating, ethanol + coating+10% EGR, ethanol + coating+20% EGR) were carried out. We observe that the exhaust fills the combustion chamber; however, it is not involved in the combustion reaction that takes place in the cylinder due to its low oxygen content. Hence, the combustion process speed is reduced, with the result that the peak flame temperature in the combustion chamber is lowered. This dramatically affected the characteristics of the EFDE. The obtained results of EFDE scenarios were compared with the diesel scenario. Overall, it is observed that the variation in the %EGR rates has a significant impact on the performance, emission, and combustion characteristics of EFDE.

Effect of EGR on diverse characteristics of diesel engine operated with corn seed biodiesel blend

ABSTRACT Transportation sector and industrialisation both are having a major impact on the economic development and ecological nuisance of any country across the globe. NOx is a highly toxic gas, released from the combustion of diesel fuel. In this current experimental work, controls of NOx emissions are examined by using Exhaust Gas Recirculation (EGR). The investigational unit is operated with corn seed oil biodiesel blend. Performance, combustion and emission features are investigated at different EGR ratios (5%, 10% and 15%, respectively), and results are compared with diesel fuel. From the analysis of the experimental results, it is concluded that NOx emissions are decreased by increasing the EGR ratio. However, a small penalty of engine performance and increased soot formation are observed at a higher EGR ratio. From the experimental test results, it is confirmed that EGR technique implementation generated excellent results for the control of harmful NOx emissions.