Engine Emission Characteristics Research Articles

Performance and Emission Characteristics of a High-Speed Diesel Engine Using a 20% Palm Oil Ester and Ethyl Alcohol Blend

Performance and Emission Characteristics of a High-Speed Diesel Engine Using a 20% Palm Oil Ester and Ethyl Alcohol Blend

Effects of different ammonia energy ratio on soot formation and oxidation in an ammonia diesel dual-fuel engine

Due to environmental pollution and energy crises, zero‑carbon fuel ammonia (NH3) has attracted extensive attention as an alternative fuel for engines. In this paper, the effects of ammonia energy ratio (AER) and injection strategy on particulate emission characteristics of an ammonia diesel dual-fuel engine were examined by merging experimental and simulation results; additionally, soot formation and oxidation mechanism were investigated. Results showed that the reduction in particulate emission was substantially higher than the increase in AER. When AER increased to 60 %, the reduction in particulate mass concentration reached 97.5 %. The initial soot formation area gradually moved to the bottom of the piston bowl with increasing AER. When the piston reached the top dead center, the high-soot-concentration area was shifted to the center of the piston bowl as AER increased. The contents of acetylene (C2H2) and methyl (CH3) reduced considerably, which restricted the formation of soot precursors. With AER increasing, the contents of nitric oxides (NOx) and other nitrogen-containing species increased and reacted with CH3 and other carbon-containing species, which effectively reduced the number of C in soot formation pathway, thereby lowering particulate emissions. As AER increased, hydroxyl (OH) involved in soot formation gradually decreased, and only 14 % of OH was involved in the oxidation of n-heptane at 60 % AER, which was favorable for reducing the soot formation rate. Furthermore, OH is a substantial species in soot oxidation. The introduction of ammonia caused an increase in OH, which facilitated the removal of soot. The decrease in hydrogenium (H) hindered the hydrogen–abstraction–acetylene–addition (HACA) reaction, further limiting the soot surface growth. By optimizing the injection timing and AER, particulate emission was lowered to 4.31 × 10−5 μg/cm3, and particle size was reduced by 64.2 % when AER was 60 %, injection timing was −20° CA ATDC, and injection pressure was 60 MPa.

Effects of exhaust gas recirculation and ethanol-gasoline blends on combustion and emission characteristics of spark ignition engine

The combined influences of exhaust gas recirculation (EGR) and ethanol-gasoline blends on the combustion process and emissions of a single-cylinder spark ignition engine were numerically examined. Four different EGR values were employed, i.e. 0%, 2.5%, 5%, and 10%, to reveal the effect of EGR on engine performance. The engine was operated at a load of 100% and a speed of 3000 rpm. The peak values of in-cylinder pressure and temperature gradually decreased as increasing the EGR ratios. These peaks move towards the TDC as increasing the ethanol fraction in blends due to high oxygen in the mixture and burning flame speed in the cylinder. Ethanol fractions ranging from 5% to 15% can effectively improve the negative effects of EGR ratios. When increasing the ethanol fraction, the CO2 rapidly increased and concentrated around the TDC. The NOx emissions are significantly increased with increasing ethanol fraction. In the case of pure gasoline, the NOx emissions are substantially suppressed and exhibit a remarkably low value as increasing the EGR ratios. The best combination for diluting NOx emissions to a very low level is ethanol fraction ranging from E5 to E10, while the EGR rates range from 5% to 10%.

Conjoint impact of modified HHO system, compression ratio variation, and tribological enhancement of steel piston ring substrates on performance and emission characteristics of a spark-ignition engine

In these times of efforts to develop high-efficiency hydrogen-adopted or hydrogen-fueled internal combustion engines (ICEs), and concerns related to electric vehicles such as battery cost, drawbacks in harsh winter climates, low range, etc., it is important to generate original ideas in line with the manufacturing of ICEs with improved efficacy. Accordingly, this study presents a comprehensive experimental investigation to observe the cooperated effects of pulse width modulation (PWM)-controlled hydroxy (HHO) gas introduction and improvement in tribological performance of piston ring-cylinder liner mechanism on performance and emission characteristics of a spark-ignition (SI) engine (co-system). The variation of compression ratio (CR), influence of two electrolyzer types of tube electrolyzer (TE) and plate electrolyzer (PE) for production of HHO gas, and zeta potential (ZP)-based dynamic light scattering (DLS) analysis to specify the optimal catalyst concentration in de-ionized water were also observed. Electron cyclotron resonance-chemical vapor deposition (ECR-CVD) method was utilized to bombard the piston ring substrates with diamond-like carbon (DLC) atoms under high energy plasma to improve the mechanical strength of the friction surface. Using linear tribometer, the uncoated (UPR) and coated piston rings (CPR) underwent friction tests to determine the wear rate (WR), and coefficient of friction (COF) which have substantial contribution to frictional losses. The surfaces of the samples were visualized via scanning electron microscopy (SEM) and atomic force microscopy (AFM) before and after abrasion tests to analyze carbon coating and its effects on tribological performance. The observations depicted that HHO flowrate needs to be varied as the engine load and CR change, and based on these observations, PWM control unit was designed, manufactured and reprogrammed so as to adjust electrical power consumption of HHO system when needed. The aforementioned analyses ensured optimization of the overall system so as to maximize the efficiency of the test engine. The co-system with optimized parameters (CPR + HHO + PWM) yielded an increase in average brake power (Pe) up to 31%, and average reductions in specific fuel consumption (β), carbon monoxide (CO), unburned hydrocarbon (UHC), and nitrogen oxide (NOx) emissions by 17%, 25%, 19%, and 14%, respectively at engine load range from 20% to 100%. It is expected that this study will be a good guide in terms of developing high-efficient ICEs due to promising results provided by the co-system.

Enhanced methanol production from recycled methanotrophic biomass and its effect on the emission and performance characteristics of a four-stroke compression ignition engine

Methanol production was demonstrated through recycling of Methylosinus trichosporium biomass to curtail time and resources incurred towards recurrent biomass generation. Cumulative methanol titer of 3.6 g/L was achieved after three cycles of biomass reutilization. Methanol was recovered from cultivation medium using distillation attaining a maximum purity of 94.74 %. Different blends of methanol (0–20 % v/v) with diesel were evaluated for their suitability as alternate transportation fuel. Physicochemical properties of diesel-methanol blends either improved or exhibited equivalence relative to pure diesel, as control. The blends were investigated for their effect on emission and performance characteristics of four-stroke compression ignition engine under varying engine loads (25, 50, 75 and 100 %). Brake specific emissions of CO, hydrocarbon and H2S decreased with increasing methanol content in the blend, attaining maximum decrements of 38.8–46.5 %, 39.8–60.7 % and 85.4–87.8 %, respectively, with 20 % methanol-containing blend (M20) under varying engine loads. On the other hand, brake specific NOx emission increased by 27.7–34.8 % under the same conditions. Superior performance parameters e.g., brake specific fuel consumption (0.29 kg kW−1h−1), brake specific energy consumption (12.9 MJ kW−1h−1) and brake thermal efficiency (28 %), were achieved using M20, while mechanical efficiency (80.8 %) exhibited equivalence with pure diesel.

Experimental investigation on diesel engine performance, combustion, and emissions characteristics with Tucuma and Ungurahui biodiesel blends

The study conducted an experimental investigation of diesel engine performance, emissions, and combustion characteristics using Tucuma and Ungurahui biodiesel blends. Higher yield (greater than 99.4%), lower viscosity than diesel, and higher cetane number of these fuels have motivated a comprehensive investigation of the effect of these fuels on diesel engines. Four blends were tested in the engine by keeping diesel as the benchmarking fuel. The engine was operated at full load conditions, and the results were investigated with respect to brake power (BP). Results indicate that biodiesel blends showed similar combustion behaviour to that of diesel. Next to diesel, TB10 and UB10 showed better brake thermal efficiency (BTE) and lower brake-specific fuel consumption (BSFC). Higher peak pressures and heat release rates (HRR) are observed for the TB10 compared to the diesel operation. Moreover, prolonged combustion was observed for the four biodiesel blends during the diffusion and late combustion phasing. With the increase in BP, slightly higher HC emissions are observed for all the blends except for TB10 compared to diesel. Similarly, a slight increase in CO emissions is also observed for all the blends at higher BP. Higher acid values of both fuels are the likely cause of increased HC and CO emissions at higher BP. NOx emissions are slightly higher for both fuels, among these UB10 has shown lower NOx than other blends. The study concludes that TB10 has demonstrated better performance (near diesel) and combustion rates (better than diesel); however, emissions like CO and NOx are slightly higher than others. The study recommends blending TB10 and UB10 with the alcohols, ethers, and nanoparticles as they can reduce NOx and CO emissions.

Enhancing Combustion Efficiency: Utilizing Graphene Oxide Nanofluids as Fuel Additives with Tomato Oil Methyl Ester in CI Engines

The research aims to conduct a thorough examination of the combustion, injection, performance, and emission characteristics of a diesel engine below different engine loads, as well as the synthesis of graphene oxide (GO) nano fuels and their utilization in combination with Tomato Oil methyl ester (TOME) and diesel fuel blend. The (GO), plays a vital role in the pre-mixed combustion phase of diesel engines. Addition of GO nano fuels enhances the high-pressure combustion stage, resulting in increased maximum pressure and heat release rate (HRR). TOME (B20GO75) and TOME (B20GO100) exhibit comparable HRR to diesel due to improved fuel characteristics and quicker ignition delay duration. While TOME (B20) shows a slight decrease in (BTE) compared to diesel, the addition of GO improves BTE, with TOME (B20GO50) displaying the highest BTE at full load, indicating enhanced combustion efficiency. Moreover, GO addition leads to a reduction in carbon monoxide (CO) and hydrocarbon (HC) emissions, with emissions decreasing as the dosage of GO increases. However, NOx emissions initially decrease with TOME (B20) compared to diesel but increase with higher GO dosages. Smoke emissions increase with TOME (B20) but decrease with higher GO dosages. Overall, the incorporation of GO nano fuels into TOME biodiesel fuel blends demonstrates potential for improving engine performance and reducing emissions.

Effect of Injector Type and Intake Boosting on Combustion, Performance, and Emission Characteristics of a Spray-Guided Gasoline Direct Injection Engine—A Computational Fluid Dynamics Study

<div>In general, GDI engines operate with stratified mixtures at part-load conditions enabling increased fuel economy with high power output, however, with a compensation of increased soot emissions at part-load conditions. This is mainly due to improper in-cylinder mixing of air and fuel leading to a sharp decrease in gradient of reactant destruction term and heat release rate (HRR), resulting in flame quenching. The type of fuel injector and engine operating conditions play a significant role in the in-cylinder mixture formation. Therefore, in this study, a CFD analysis is utilized to compare the effect of stratified mixture combustion with multi-hole solid-cone and hollow-cone injectors on the performance and emission characteristics of a spray-guided GDI engine.</div> <div>The equivalence ratio (<i>ϕ</i>) from 0.6 to 0.8 with the constant engine speed of 2000 rev/min is considered. For both injectors, the fuel injection pressure of 200 bar is used with 60° spray-cone angles. For lean boosting conditions, intake pressures of 1 bar, 1.2 bar, and 1.4 bar are maintained for 0.8 equivalence ratio cases for both injectors. Results from the CFD analysis are compared with those of the available experimental results with good agreement. Analyzing the results, naturally aspirated and intake boosting conditions for <i>ϕ</i> of 0.8, mixture distribution and flame propagation for the multi-hole solid injector are better than hollow-cone injector. Also, for the <i>ϕ</i> of 0.8, naturally aspirated mode, the soot emissions by the hollow-cone injector are higher by about 90%, and the NO<sub>x</sub> emissions are higher by about 19% compared to that of the multi-hole solid-cone injector. Under boosted intake pressure conditions, for the hollow-cone injector, the soot emissions are higher by about 97%–99%, and NO<sub>x</sub> emissions are higher by about 7%–6% compared to the multi-hole solid-cone injector. Also, HC and CO emissions are considerably lower for the hollow-cone injector than that of the multi-hole solid-cone injector.</div>

A comprehensive assessment over the environmental impact and combustion efficiency of using ammonia/ hydrogen/diesel blends in a diesel engine

To reduce the dependence on traditional fossil fuels and promote low-carbon emissions, this article takes a four-cylinder four-stroke diesel engine as the research object and constructs a simulation model. It mainly simulates and studies the effects of different ammonia energy substitution rates (AESR) and hydrogen energy substitution rates (HESR) on the combustion and emission characteristics of diesel engines. Under the full load condition, the AESR was simulated within the range of 10 %–50 %. Subsequently, HESR of 0, 2 %, 4 %, 6 %, 8 % at AESR of 10 %, 20 %, 30 %, 40 %, and 50 % are set for further study. The research results indicate that with the increase of AESR, the combustion performance of the engine is improved. The emissions of NOx, CO2, and soot are reduced, but the emissions of unburned ammonia are significantly increased. Adding hydrogen to ammonia-diesel blended fuel can effectively reduce unburned ammonia emissions. Based on the comprehensive analysis results, it is more appropriate to choose a HESR of 4 % when the AESR is 10 %.

The effect of fusel oil and waste biodiesel fuel blends on a CI engine performance, emissions, and combustion characteristics

In this study, experimental engine tests were conducted to investigate the combustion, performance, and emission characteristics of a diesel engine using a fuel blend composed of diesel, biodiesel, and fusel oil. In the study, which was carried out by using fuels obtained from different wastes together in a diesel engine. Seven different fuels were prepared for experiments by adding waste cooking oil (30% and 50%) and fusel oil (5% and 10%) by volume to commercial diesel fuel. The tests were carried out on the Lombardini LDW 1003 engine, a three-cylinder diesel engine, at four different engine loads (10, 20, 30, and 40 Nm), and a constant speed (2000 rpm). The experimental results revealed that the use of WCO generally led to increased NOx emissions which generally decreased with the fusel oil addition to the fuel mixture. Considering diesel fuel as a reference at maximum load conditions, there was a 12.63% increase in NOx emissions with 50% WCO. A 2.45% decrease in NOx emissions was achieved by adding 10% fusel oil. Furthermore, HC emissions decreased with the addition of both fusel oil and WCO at all load levels. When diesel fuel is taken as a reference at maximum load conditions, a 90% reduction in HC emissions was achieved by adding 50% WCO, and a 50% reduction in HC emissions was achieved by adding 10% fusel oil. Additionally, when diesel fuel is taken as a reference at maximum load condition, it was observed that a 0.05% increase in the maximum cylinder pressure value with the addition of 50% WCO and a 2.09% increase in the maximum cylinder pressure value with the addition of 10% fusel oil.

Impact of multi-walled carbon nanotubes (MWCNTs) on hybrid biodiesel blends for cleaner combustion in CI engines

This study investigates the influence of multi-walled carbon nanotubes (MWCNTs) and hybrid biodiesel blends on the performance, combustion, and emission characteristics of a compression ignition engine. The hybrid biodiesel comprises waste frying oil methyl ester (WFOME), sesame oil methyl ester (SOME), and ultra-low sulfur diesel (ULSD) blended at 20 %:80 % by volume (B20). MWCNTs were added into B20 at 25 ppm and 50 ppm concentrations (B20-25MWCNT and B20-50MWCNT). Experimental analysis was conducted under varying engine loads and injection pressures, complemented by CFD simulations. Results demonstrate that the addition of MWCNTs significantly enhances B20 blend performance, with B20-50MWCNT exhibiting a 25 % increase in brake thermal efficiency and a 17 % reduction in brake specific fuel consumption compared to neat B20. Additionally, the incorporation of MWCNTs resulted in notable reductions in harmful emissions. NOx emissions for the B20 + 50MWCNT blend were reduced by up to 36 % compared to diesel and 43 % compared to B20. Smoke opacity and particulate emissions also showed significant decreases, highlighting the cleaner combustion facilitated by the presence of MWCNTs. The CFD simulations provided detailed insights into the combustion process, validating the experimental findings and elucidating the mechanisms behind the observed improvements. The enhanced fuel atomization, better fuel-air mixing, and catalytic properties of MWCNTs were identified as key factors contributing to the superior performance and reduced emissions.

Extraction and characterization of Cucumis melon seeds (Muskmelon seed oil) biodiesel and studying its blends impact on performance, combustion, and emission characteristics in an internal combustion engine

This study examines the performance, combustion, and emissions characteristics of a single-cylinder internal combustion diesel engine when fueled with a blend of diesel and biodiesel derived from muskmelon seeds. The kinematic viscosity of the extracted muskmelon seed oil was 6.1 cSt at 40 °C, which is higher than the kinematic viscosity of petroleum diesel of 2.6 cSt. Muskmelon biodiesel was further analyzed using thin-layer chromatography (TLC) and high-voltage separator tests. A comparison of the fuel properties of muskmelon biodiesel with conventional diesel fuel revealed that muskmelon biodiesel could be used alone or in a diesel–biodiesel blend to fuel compression diesel engines. In this study, muskmelon seed biodiesel was blended with diesel fuel at proportions of 10 %, 20 %, and 50 % (BD10, BD20, and BD50, respectively). At a relatively low rotational speed of 1200 rpm, the brake thermal efficiency (BTE) of the engine operated with BD10 and BD20 blends were 36.1 % and 36.0 %, respectively, while the brake-specific fuel consumption (BSFC) of the two blends were 0.260 kg/kWh, and 0.262 kg/kWh, respectively. These values closely resemble those typically observed in diesel fuel engines. Indeed, the average BTE of the BD20 blend was only 3.24 % less than the average BTE of diesel fuel. Diesel fuel generates less NOx and SO2 emissions compared to biodiesel blends: BD100 emitted the most NOx pollution of all fuels tested. In addition, BD10 released significantly more SO2 emissions compared to the other fuels tested. However, the BD20 blend outperformed all other blends in terms of CO, NOx, and SO2 emissions at high engine speeds. The only exception was H2S emissions, which were higher than BD50 and BD100. BD20 also exhibited significantly reduced CO emissions compared to diesel fuel, while BD10 emitted significantly more CO emissions than the other biodiesel blends. Our findings revealed that BD20 exhibited the best engine performance and lower emissions among all fuels tested. In other words, BD20 is the ideal fuel blend for use in diesel engines and does not require any alterations to the engine. Muskmelon waste seeds represent a non-edible waste stream that can be exploited in the production of biodiesel fuel, allowing for the upcycling of a potentially problematic thermochemical conversion feedstock. This potentially valuable use for waste muskmelon seeds in the energy sector could address the wastefulness associated with this particular waste stream.

The influence of injection pressure and exhaust gas recirculation on a VCR engine fueled by microalgae biodiesel

AbstractBiodiesel has been chosen as a decent alternative to diesel in the context of establishing environmentally pleasant conditions and saving petroleum‐based resources for future generations. It is well‐established that biodiesel‐powered diesel engines may achieve outcomes equivalent to those of diesel engines. The current investigation was conducted to study the effect of injection pressure (190, 210, and 230 bar) and exhaust gas recirculation (EGR) (5%, 10%, and 15%) on a single‐cylinder variable compression ratio (VCR) diesel engine running using a B20 (20% MB + 80% PD) blend of microalgae biodiesel (MABD). This experiment was conducted in two stages. During the first stage of experimentation, the efficiency and emission characteristics of a diesel engine with a B20 blend of MABD at various fuel injection pressures and fresh air were investigated. During the second phase, fresh air was mixed with 5%, 10%, and 15% exhaust gases, and the experiment was conducted. It was discovered that increasing injection pressure to 230 bar provided considerable improvements. Brake thermal efficiency increased by 2.35%, brake‐specific fuel consumption decreased by 3.57% and pollutants such as carbon monoxide (CO), hydrocarbon, and smoke were reduced by more than 50% compared to conventional diesel. These reductions were similarly significant (over 22%) as compared to the B20 blend at lower injection pressure (210 bar). However, there was a slight trade‐off: nitrogen oxide (NOx) emissions increased partially (3.14%), while exhaust gas temperature (EGT) increased by 1.72% at a higher pressure. The study then investigated the influence of EGR (5%, 10%, and 15%) at various injection pressures. The optimal value seems to be 10% EGR at 230 bar injection pressure. This combination substantially reduced NOx emissions (by over 41% compared to the normal B20 blend) and EGT (by more than 8%), while having no notable effect on other performance or emission variables. Overall, the results show that employing a B20 MABD blend with high injection pressure (230 bar) and moderate EGR (10%) improves engine performance while reducing hazardous emissions.

Effect of excess air ratio and ignition timing on the combustion and emission characteristics of the ammonia-hydrogen Wankel rotary engine

As a hydrogen carrier, ammonia can suppress knock and enhance thermal efficiency of the hydrogen-fueled Wankel rotary engine (WRE), and achieve zero carbon emissions. This research established a three-dimensional fluid dynamics model coupled with detailed reaction kinetics of ammonia and hydrogen and verified it based on experiments. Incorporating 10% volume fraction of ammonia into the hydrogen-fueled WRE eliminates knock and decreases the excess air ratio (λ) from 1.8 to 1.4, effectively improving the indicated mean effective pressure (IMEP). The results indicate that when λ exceeds 1.4, flame propagation accelerates with higher concentration of the mixture. This enhances peak in-cylinder pressure and heat release rate, but it results higher NOx emissions. As λ varies from 1.8 to 1.4, NOx emission levels rise by 47.4%. At λ ≤ 1.2, the rapid flame propagation leads to short combustion duration, diminishing the power output. At this stage, the NO formation is dominated by H radicals, and the NOx production reaches its minimum value at λ of 1.0. In summary, the ammonia-hydrogen WRE achieves optimal performance at λ of 1.4 and ignition timing of −5 °CA after top dead center, the indicated thermal efficiency reaches 36.9% and the IMEP achieves 0.683 MPa.

Predicting combustion, performance, and emission characteristics of a compression ignition engine utilising coconut oil methyl ester and MoO3 nanoparticles

The present study used a blend of biofuel and nanoparticles to examine the effectiveness and emission properties of a four-stroke, single-cylinder, direct-injection diesel engine with an injection pressure of 250 bar. The use of MoO3 in biodiesel enhances its environmental sustainability and dependability, making it a promising substitute for traditional diesel fuel. The study emphasises the ecological advantages of using a combination of coconut oil and MoO3 to accomplish the production of renewable energy. MoO3 nanoparticles ultimately function as an oxidation catalyst, enhancing combustion. A study with MoO3 nanoparticles at 50 and 100 ppm concentrations was carried out. Utilising a photo spectrometer, stability was determined. The CI engine demonstrated improved thermal efficiency and reduced Fuel Consumption compared to diesel, both at full load conditions and at 64.5 bar pressure. The performance, combustion, and emission parameters were precisely forecasted using Design Expert, exhibiting a robust connection with the testing results. The Rb values for Brake Specific Fuel Consumption (BSFC), Brake Thermal Efficiency (BTE), Peak Cylinder Pressure (P-CA), Net Heat Release Rate (NHRR), Crankcase Heat Release Rate (CHRR), Carbon Monoxide (CO), Unburned Hydrocarbons (UHC), Nitrogen Oxides (NOX), and Smoke Opacity are 0.997, 0.9998, 0.8898, 0.979, 0.9838, 0.9815, 0.9917, 0.9958, and 0.9261 respectively.

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.

Experimental investigation of engine performance and emissions, and characterization, of waste transformer oils and diesel blends with biodiesel produced from olive oil wastes in a CI engine

In this study, five different fuel blends were prepared by mixing biodiesel obtained from olive oil wastes using transesterification method, waste transformer oil, and Euro diesel in different ratios. The important physicochemical properties of the prepared fuel blends and produced biodiesel were determined by gas chromatography, Fourier transform infrared spectroscopy, and thermogravimetric analysis/differential scanning calorimetry analyses, and their characterizations were carried out. Then, the effects of the prepared fuel blends on engine performance and emission characteristics were investigated in a compression ignition engine. The experiments were performed with five different fuel blends (TD30, TD30B10, TD30B20, TD30B30, and D100) at 1000, 1500, 2000, and 2500 rpm. At all speeds, each fuel blend produced an average torque value that was highest for D100 fuel and lowest for TD30 fuel The average BP value produced by each fuel at all engine speeds was highest in D100 fuel and lowest in TD30 fuel. The results of the experiments showed that there was a 23.98% decrease in the average NOx emissions of TD30 fuel blend compared to the average NOx emissions of D100 fuel at all engine speeds. It was observed that all important fuel properties such as density, kinematic viscosity, and pour and cloud points of all fuel blends met the fuel standards.

Role of hydrogen-enrichment for in-direct diesel engine behaviours fuelled with the diesel-waste biodiesel blends

Carbon footprint indicates the total amount of greenhouse gases released into the atmosphere by individuals, institutions and countries. The widespread use of fossil fuels is a big player which increases the carbon footprint. Therefore, switching to sustainable alternatives in energy production and consumption is an effective step in combating climate change, as well as efforts to prevent the depletion of fossil fuels. In this regard, although biodiesels offer a solution to the depletion of fossil fuels, with this advantage, the effects of production processes and use on environmental sustainability should be taken into consideration. Many scientific studies have shown that engine performance remains below standards with biodiesel. The availability of hydrogen as an energy carrier in cylinder to overcome the above-mentioned negative situations has recently become a popular topic for fuel researchers. In this work, the diesel-biodiesel fuels were blended proportionally and tested on a three-cylinder water-cooled in-direct diesel engine at varying loads (15, 30, 45, and 60 Nm) and a constant engine speed of 2200 rpm for observing the effects of test fuels on combustion, performance, and emissions characteristics of diesel engine. First of all, conventional diesel fuel (D) was used to obtain reference data, and then B20 fuel obtained by mixing waste cooking oil with 20 % by volume of diesel fuel was used. The remaining 4 fuels are test fuels obtained by giving hydrogen from the intake manifold at different flow rates (10, 20, 30, and 40 L/min) in addition to B20 fuel. These fuels are called B20 + 10 Lpm H2, B20 + 20 Lpm H2, B20 + 30 Lpm H2 and B20 + 40 Lpm H2, respectively. As a result, the BSFC of B20 fuel increased by 8.78 % compared to diesel fuel, and then the addition of hydrogen dropped the BSFC value by 8.8 %, 13.02 %, 17.16 %, and 22.12 % for B20 + 10 Lpm H2, B20 + 20 Lpm H2, B20 + 30 Lpm H2, and B20 + 40 Lpm H2, respectively. Hydrogen enrichment also had a positive impact on BTE. Although the BTE dropped by 6.14 % in B20 fuel compared to diesel, it increased by 4.51 %, 5.05 %, 5.62 %, and 7.12 % in B20 + 10 Lpm H2, B20 + 20 Lpm H2, B20 + 30 Lpm H2 and B20 + 40 Lpm H2 fuels, respectively. The addition of 10, 20, 30, and 40 Lpm H2 to B20 fuel reduced NOx emissions by 31.25 %, 33.08 %, 38.87 %, and 41.46 %, respectively, and also reduced CO emissions by 17.47 %, 30.73 %, 51.8 % and 59.04 % respectively.

Using CRITIC-TOPSIS and python to examine the effect of 1-Hepatnol on the performance and emission characteristics of CRDI CI engine with split injection

Recently, biofuels with higher alcohol content have become a promising alternative to diesel fuel. These fuels are appealing because they are sustainable, renewable, and possess attractive fuel properties. This study uses a split injection strategy to analyze the performance and emissions of a CRDI diesel engine fueled by 1-heptanol. The work involved testing different fuel blends, ranging from 10 % to 30 %, while maintaining a constant engine speed of 1500 rpm and varying the operating load between 0 kg and 12 kg in 4 kg increments. During the second stage, the CRITIC-TOPSIS method determines the objective weights and rankings of various criteria and alternatives. A Python approach based on machine learning was used to ensure the CRITIC-TOPSIS results were accurate. Seven criteria were evaluated to maximize BTE while minimizing BSFC, NOx, smoke opacity, HC, CO, and CO2. The experimental results showed a slight drop of 2.98 % in BTE and an increase of about 13.33 % in BSFC. NOx and smoke opacity were reduced by 7.13%–4.53 %, while there was a 12.12 % increase in HC, 6.45 % higher CO, and a 5.5 % increase in CO2 at full load. Adding 1-heptanol to diesel and using a split injection strategy significantly reduced NOx and smoke opacity. The final ranking and best blend are determined using CRITIC-TOPSIS and Python algorithms to estimate performance and emissions criteria. At a load of 4 kg, D100 ranks first with a relative closeness value of 0.642, while at a pack of 8 kg, the blend HP20D80 ranks first with a relative closeness value of 0.633. According to the rankings, the HP20D80 blend is the best option for achieving optimal performance and reduced emissions in CRDI diesel engines. A research paper has presented a unique approach to multiple criteria decision-making (MCDM) validated using a Python algorithm. This method can assist decision-makers in making better-informed choices when faced with MCDM problems that involve various criteria and alternatives.

Influence of Hydrogen induction on performance and emission characteristics of an agricultural diesel engine fuelled with cultured Scenedesmus obliquus from industrial waste

The use of microalgae in waste water treatment has been recognised as crucial for managing and treating effluent from industrial sources. Present study used Scenedesmus obliquus (SO) strains in industrial waste cultured medium, grown algae were collected and dried, further with dried mass to algae bio fuel by transesterification process. Four fuel blends were created by adjusting the SO concentration from 10% to 40% by volume. Then SO blend was examined with impact of hydrogen induction on compression ignition engine. The addition of H2 to SO biodiesel enhances its net calorific value because of its high calorific content.Adding H2-inducted SO proportion to diesel reduces HC, NOx, and CO levels, with a negligible performance dip. At full loads, SO40 showed a significant improvement in emission levels, with a 19.81% reduction in NOx, a 51 ppm drop in HC and 1.146% dropobserved in CO compared to diesel. For the SO10 mix, BTE and BSEC were found to be 2.86% and 2103.77 kJ/kW-hr, respectively, superior to other SO blends. Subsequently, it is of crucial significance to acknowledge the significance of the potential those microalgaeprovides for the production of sustainable energy through the reprocessing of industrial effluents.