Single Cylinder Diesel Engine Research Articles

Non-PGM Hollow Fibre-Based After-treatment for Emission Control under Real Diesel Engine Exhaust Gas Conditions

Hollow fibre (HF)-based technologies for emission control, as an alternative to the traditional monolithic technology, offers a promising route to the uptake of non-PGM catalytic systems. In this work, a series of Cu-doped LaCoO3 perovskites were investigated as potential non-PGM Diesel Oxidation Catalysts (DOC). Two HF-based modules, comprising single-channel (i.e., 1CM) and four-channel (i.e., 4CM) HFs respectively, were impregnated with the best catalyst candidate, and their performance was tested under real exhaust gas conditions, using a single-cylinder diesel engine. Compared to the 1CM, the 4CM demonstrated enhanced CO conversion, and reduced performance towards Total Hydrocarbon (THC) conversion. Overall, these findings reveal the influence of HF morphology on catalytic performance, and in turn, will contribute towards the refinement of HF-based technology for emission control, as well as enabling the transition towards non-PGM catalytic systems.

On the Influence of Engine Compression Ratio on Diesel Engine Performance and Emission Fueled with Biodiesel Extracted from Waste Cooking Oil

Despite the extensive research on biodiesels, further investigation is warranted on the impact of compression ratios on emissions and engine performance. This study addresses this gap by evaluating the effects of increasing the engine’s compression ratio on engine performance metrics—brake-specific fuel consumption (BSFC), power, torque, and exhaust gas temperature—and emissions—unburnt hydrocarbons (HCs), carbon dioxide (CO2), carbon monoxide (CO), nitrogen oxides (NOx), and oxygen (O2)—when fueled with a 20% blend of waste cooking oil biodiesel (WCB20) and petroleum diesel (PD) under various operating conditions. The viscosity of the prepared fuels was measured at 25 °C and 40 °C. Experiments were conducted on a single-cylinder diesel engine under wide-open throttle conditions at three different speeds (1400 rpm, 2000 rpm, and 2600 rpm) and two compression ratios (16:1 and 18:1). The results revealed that at a lower compression ratio, both WCB20 and petroleum diesel exhibited reduced BSFC compared to higher compression ratios. However, increasing the compression ratio from 16:1 to 18:1 significantly decreased HC emissions but increased CO2 and NOx emissions. Engine power increased with engine speed for both fuels and compression ratios, with WCB20 initially producing less power than diesel but surpassing it at higher compression ratios. WCB20 demonstrated improved combustion quality with lower unburnt hydrocarbons and carbon monoxide emissions due to its higher oxygen content, promoting complete combustion. This study provides critical insights into optimizing engine performance and emission characteristics by manipulating compression ratios and utilizing biodiesel blends, paving the way for more efficient and environmentally friendly diesel engine operations.

Analysis of the Influence of Fuel Dose on the Electrical Parameters of the Starting Process of a Single-Cylinder Diesel Engine

Analysis of the Influence of Fuel Dose on the Electrical Parameters of the Starting Process of a Single-Cylinder Diesel Engine

Effect on polytropic index, performance and emission of diesel engine using hydrogen as gaseous fuel with additive di-tert butyl peroxide

Diesel engines are commonly used due to its higher reliability and better fuel conversion efficiency. However, it produces exhaust emissions like carbon dioxide (CO2) and particulate matter (PM). Hydrogen gas is regarded as a clean fuel as it is free from carbon. The addition of hydrogen fuel enhances the burning rates and extends the flammability limits of fossil fuels, and therefore has the potential of reduced exhaust emission in diesel engines operating on dual fuel mode. This paper has investigated the effect of hydrogen addition to the performance and emissions of a single-cylinder diesel engine, working in dual fuel mode with additive di-tert butyl peroxide (DTBP). About 25% hydrogen was introduced into the cylinder on a mass basis via the engine intake manifold with the addition of additive di-tert butyl peroxide up to 5% in diesel fuel. In this experimental study, mean gas temperature, indicated mean effective pressure (IMEP), brake mean effective pressure (BMEP), polytropic index, and exhaust emissions were studied at medium (53%) and high (69%) load conditions. The indicated mean effective and brake mean effective pressure was 9.79 bar with a 3% addition of additive and 4.15 bar with the 5% addition of additive as compared with 8.71 bar and 4.11 bar diesel fuel operation. 16% hydrogen addition with 1% di-tert butyl peroxide, IMEP, and BMEP are 10.92 bar, and 4.14 bar respectively.

Modeling the impact of plastic oil obtained from xlpe cable wastes on diesel engine performance and combustion parameters with the response surface method

The world's expanding population requires alternative energy sources to meet its energy needs. One such alternative is the efficient recovery of plastic waste through pyrolysis. The liquid produced from waste plastics via pyrolysis is a valuable commodity that may serve as fuel substituted for internal combustion engines. In this study, waste plastic oil (WPO) and diesel fuel (D100) blends (10%, 20%, 30%, 40% and 50% by volume) obtained by pyrolysis of waste XLPE cables were experimentally investigated and analyzed using response surface methodology (RSM) to determine their effects on the combustion parameters of a four-stroke, single cylinder diesel engine at different engine loads (750, 1500, 2250, 3000, 3750 and 4500 W). A response surface model was constructed using a two-factor central composite complete design and analysis of variance based on the experimental results obtained. The model determined the optimum values of WPO ratio and engine load that correspond to one of the finest brake thermal efficiency (BTE), brake specific fuel consumption (BSFC), hydrocarbon (HC), carbon monoxide (CO), nitrogen oxides (NOx), and smoke emission levels. The study's optimization findings indicated that the optimal WPO ratio is 19.6%, and the optimal engine load is 2600 W. The BTE, BSFC, CO, HC, NOx, and smoke were found to be 22.3%, 332.3 g/kWh, 0.033%, 31.5 ppm, 397.9 ppm, and 1.63%, respectively, at the optimal WPO ratio and engine load. The R2 (correlation coefficient) values for BTE, BSFC, CO, HC, NOx, and smoke emissions were determined to be 99.95%, 97.76%, 98.10%, 99.74%, 99.74%, 99.79%, and 95.67%, respectively. The mean error rates, ranging from 0.64% to 4.27%, were deemed satisfactory when comparing the replies to the experimental data. The findings of this study demonstrated that the response surface method is a very efficient approach for forecasting and enhancing a diesel engine's performance and emission characteristics by using waste plastic oil.

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.

Reduction of Emissions in a Single Cylinder Diesel Engine using Blends of Diesel & Cotton Seed Oil with Unconventional Catalytic Converter

This paper investigates the feasibility of mitigating emissions from diesel engines through the combined application of alternative fuels and an unconventional catalytic converter employing cost-effective catalysts. The dwindling reserves of fossil fuels necessitate the exploration of sustainable power sources for internal combustion engines, thereby reducing our dependence on these finite resources. This study evaluated the performance parameters and emissions of a single-cylinder, four-stroke, stationary diesel engine fueled with blends of 10%, 20%, and 30% cottonseed oil in diesel (by volume). Following the identification of the optimal blend, a performance test was conducted again with the inclusion of a custom-designed and fabricated catalytic converter. Exhaust emissions were subsequently measured with and without the converter in operation. The design of the unconventional catalytic converter considered the engine's specifications, incorporating cerium oxide and sponge iron as oxidation catalysts for CO and hydrocarbon (HC) conversion. Charcoal was employed as a reduction catalyst to specifically target NOx emissions.

Design and simulation of an exhaust muffler for a single cylinder diesel engine for the Wuzheng tricycle model 7YPJ-1750PD

Design and simulation of an exhaust muffler for a single cylinder diesel engine for the Wuzheng tricycle model 7YPJ-1750PD

Predictive modeling of engine performance and emissions for castor oil ethyl ester biodiesel blends: A Gaussian process regression approach

Replacing fossil fuels with cleaner alternatives is essential. This study examines a biodiesel-diesel blend containing 8 % castor oil ethyl ester (COEE8) and its impact on engine performance, combustion characteristics, and exhaust emissions. A single-cylinder diesel engine was tested under consistent conditions: an engine speed of 1500 rpm, varying engine loads (25 %, 50 %, and 75 % of maximum torque), and compression ratios (16, 17, and 18). Engine-out emissions were measured with Testo flue gas analyzers. The results showed that COEE8 combustion significantly decreased HC, CO, and smoke emissions compared to diesel fuel but increased NOx emissions. Additionally, COEE8 exhibited comparable brake-specific fuel consumption (BSFC) and brake thermal efficiency (BTE) to diesel fuel. The optimal engine operating parameters were determined using the Non-dominated Sorting Genetic Algorithm-II (NSGA-II), a multi-objective optimization technique. Due to limited data availability, Gaussian Process Regression (GPR), a machine learning algorithm for small datasets, modeled the multi-objective functions with compression ratio and engine load as input variables. The GPR model demonstrated high prediction performance across all output parameters (BSFC, BTE, HC, smoke, NOx, and CO) for both diesel and COEE8 fuels, with average coefficients of determination (R2) of 0.9896 and 0.9953, respectively, indicating a strong correlation between predicted and actual values. The mean absolute percentage error (MAPE) was also low, averaging 3.11 % and 2.26 %, respectively, demonstrating the model's accuracy. Using the GPR model, the NSGA-II identified the optimal trade-off between NOx and smoke index for both diesel and COEE8 fuels. The optimal compression ratio was 16 for both fuels, while the optimal engine load varied, ranging from 20 % to 30 % for COEE8 and around 30 % (almost 40 %) for diesel fuel.

In-cylinder flow evolution in the horizontal plane of a motoring compression ignition engine

This study used the two-dimensional particle image velocimetry technique to quantify the in-cylinder horizontal plane velocity field evolution in a swirl-supported light-duty single-cylinder diesel engine. The data were acquired at a constant engine speed of 1600 revolutions per minute. For each case, the distance of the laser sheet from the fire deck was varied (z = 5, 10, and 20 mm) to investigate the axial variations in the flow field during the flow evolution in the compression stroke. A vortex identification algorithm was used to detect the swirl center and its deviation from the rigid body rotation. A Bessel fit was obtained using the experimental data. The result revealed that the in-cylinder flow was not axisymmetric. The swirl center approached the geometrical center as the piston approached the top dead center. The flow evolved at the farthest plane from the fire deck. The axial diffusion of angular momentum resulted in the formation of the swirl flow structure in the plane closer to the fire deck. Angular momentum analysis of a simplified geometry has been presented to explain the swirl amplification. The estimated results were compared with the experimental results to show the momentum stratification in the engine cylinder later in the compression stroke.

Assessing the impact of sargassum algae biodiesel blends on energy conversion in a modified single-cylinder diesel engine with a silica-incorporated diamond-like coated piston

ABSTRACT As coal and oil reserves deplete, the world is shifting to alternative fuels and renewable energy. Researchers are exploring a cleaner alternative to fossil fuels for powering automobiles. In this investigation, biodiesel was synthesized from brown marine algae (Sargassum algae) using transesterification process. Silica-incorporated diamond-like coating (DLC) was done on the engine piston by using the chemical vapor deposition (CVD) process with flow rate of 7sccm of C2H2. Three different coating thicknesses, such as 50,100, and 150 µm, were employed on the CI engine piston. Mechanical properties such as hardness, wear, and microstructure analysis were investigated. Analysis of mechanical characteristics reveals that pistons with a 100 μm coating have enhanced characteristics compared to those with other pistons. Using a 100 μm silicon coated piston on a single-cylinder Kirloskar engine, four blends (B10, B20, B30, and B40) were compared to neat diesel. At maximum engine load conditions, the B40 blends produced 42 ppm of HC whereas neat diesel with 19 ppm which is 57% higher than diesel and CO emission concentration increased by 4.9% than diesel. Similarly, brake-specific fuel consumption was observed at maximum load conditions for diesel with 0.18 kg/kWh and 0.20 kg/kWh for B10D90 which is 9.54% higher than diesel. As a result, it is critical to recognize the importance of sargassum’s potential for producing sustainable energy toward green globalization.

Investigation into the Impact of Piston Bowl Size on Diesel Engine Characteristics with Changes in Fuel Injection Pressure and Boost Pressure

This study presents the effects of piston bowl size on the characteristics of a four-stroke single-cylinder diesel engine, which is considered in relation to changes in factors such as fuel injection pressure and turbocharger pressure. The study was carried out by 3D modeling using AVL Fire with an omega combustion chamber size and dimensions determined by the ratio between the diameter and depth of the piston bowl, which varies from 3.4 to 10.0. Additionally, the turbocharger pressure varies from 0.15 to 0.45 MPa at an engine speed of 1400 rpm and fuel injection pressure up to 300 MPa. The results show that the engine reaches the best values of indicated power, fuel efficiency, and a substantial decrease in emissions of nitrogen oxides at a turbocharger pressure from 0.25 to 0.35 MPa and with a ratio of the diameter to the depth from 7.8 to 10. However, the injection angle changes slightly, and the penetration depth and the tip velocity decrease with increasing boost pressure. While the piston bowl parameters only impact significantly on the tip velocity, the penetration and the spray angle are almost unchanged. In addition, the variation in the diameter of the combustion chamber has an influence on the fluctuation of the spray tip velocity and penetration.

Impacts of pine oil and hydrogen induction with hemp oil methyl ester on dual fuel reactivity controlled compression ignition combustion in diesel engine

AbstractThe current research focuses on the impacts of pine oil injection and hydrogen induction separately with hemp oil methyl ester (HOME) in the single cylinder diesel engine in dual fuel‐reactivity controlled compression ignition (DF‐RCCI) combustion mode. The engine was tested under a DF‐RCCI mode for the different energy shares of 10% pine oil with HOME (10P‐HOME), 30% pine oil with HOME (30P‐HOME), 3‐lpm hydrogen with HOME (3‐lpmH2‐HOME), and 6‐lpm hydrogen with HOME (6‐lpmH2‐HOME) separately at 345 °CA bTDC of low reactivity fuel (pine oil and hydrogen) and 23°C bTDC injection timing of high reactivity fuel (HOME). The results showed a higher Brake Thermal Efficiency (BTE) of 7.44%, 5.32%, 5.72%, and 2.46% for 6‐lpmH2‐HOME, 3‐lpmH2‐HOME, 30P‐HOME, and 10P‐HOME fuel shares, respectively, over the conventional diesel combustion (CDC) at full load. 30P‐HOME, 3‐lpmH2‐HOME, and 6‐lpmH2‐HOME fuel combinations recorded 4.08% 4.42%, and 5.69% lower brake specific fuel consumption (BSFC), respectively, at full load. When comparing DF‐RCCI combustion to CDC, an increase in the heat release rate (HRR) of 2.89%–26.50% and a rise in peak cylinder pressure of 0.77%–12.99% were observed. The 30P‐HOME, 3‐lpmH2‐HOME, and 6‐lpmH2‐HOME emit less smoke in DF‐RCCI combustion mode by 13.06%, 4.84%, and 7.26%, respectively at full load condition. When using 30P‐HOME the exhaust gas temperature (EGT) decreased by 3.50% at full load condition. At part and full load conditions, the 30P‐HOME fuel share reduced oxides of nitrogen (NOX) emissions by 3.93% and 5.26%, respectively.

Mathematical modelling for predicting performance and emissions of a diesel engine fuelled with palm kernel biodiesel–diesel-diethyl carbonate fuel blends

The search for environmentally friendly and sustainable alternatives to conventional diesel fuels has prompted investigations into blends of biodiesel and oxygenated additives like diethyl carbonate. This study focuses on developing mathematical models to predict the performance and emissions of a single-cylinder diesel engine running on palm kernel biodiesel blended with varying proportions of diethyl carbonate. Response Surface Methodology with a general factorial design was employed to create mathematical models for brake thermal efficiency, brake-specific fuel consumption, hydrocarbon, carbon monoxide, and oxides of nitrogen emissions. The two input variables were engine load (five levels) and diethyl carbonate percentage in the fuel blend (five levels). Second-order models were developed, and model fit was evaluated using analysis of variance (ANOVA) at 95% confidence. The developed RSM models showed excellent fit with high R-squared values close to unity, satisfying the model adequacy criteria. ANOVA revealed the models to be statistically significant predictors of the response variables based on load and diethyl carbonate percentage. The optimum operating condition for best performance and emissions balance was found to be 71% load and 10% diethyl carbonate inclusion. The study emphasises the importance of alternative fuels in mitigating environmental pollution and reducing dependence on fossil fuels.

Ammonia-enriched biogas as an alternative fuel in diesel engines: Combustion, performance and emission analysis

This study investigates the potential of ammonia as a secondary fuel in diesel engines, amidst the rising interest in alternative fuels and the growth of electric vehicles. Unlike hydrogen, with its higher flammability and safety concerns, ammonia offers a viable, sustainable fuel source. A single-cylinder diesel engine was utilized to assess engine performance and combustion characteristics using ammonia gaseous blends. Ammonia was combined with biogas to mitigate its corrosive effects and compensate for its lower heating value. Th entire best conducted with constant ammonia flow rate of 30 LPM. Diesel was mixed with biogas in compositions of 10 LPM, 20 LPM and 30 LPM, and tested under engine loads of 25%, 50%, 75%, and 100%. The blend with the highest ammonia concentration (B30B3) exhibited the largest heat release rate, highlighting a strong correlation between ammonia content and heat release levels. This is attributed to the premixed combustion phase and the accelerated flame speed associated with ammonia. An increase in ammonia content resulted in higher brake thermal efficiency and reduced brake specific fuel consumption. All ammonia-inclusive blends showed a decrease in hydrocarbon and carbon monoxide emissions, with the lowest emissions observed in the B30B3 blend. However, the high flammability of biogas in the B30B3 blend, compared to diesel, and enhanced fuel atomization, led to increased nitrogen Oxides formation. The results clearly indicate that combination of ammonia along with the biogas enhances the combustion and reduces greenhouse gas emissions. Findings of this study provides valuable insights into the use of ammonia as a sustainable alternative in diesel engines, offering a improved balance between combustion efficiency and environmental impact.

Laboratory Tests of Electrical Parameters of the Start-Up Process of Single-Cylinder Diesel Engines

Despite continuous work on new power systems for vehicles, machines, and devices, the combustion engine is still the dominant system. The operation of the combustion engine is initiated during the starting process using starting devices. The most common starting system used is the electric starter. The starting process of an internal combustion engine depends on the following factors: the technical condition of the starting system, technical condition of the engine, battery charge level, lubricating properties, engine standstill time, engine and ambient temperature, type of fuel, etc. This article presents the results of laboratory tests of the electrical parameters of the starting process of a single-cylinder compression–ignition engine with variable fuel injection parameters and ambient temperature conditions. It was confirmed that for the increased fuel dose FD2, higher values of the measured electrical parameters (Imax, Pmax, and Pmed) were obtained compared to the series of tests with the nominal fuel dose. Knowledge of the values of the electrical parameters of the starting process is important not only for the user (vehicle driver, agricultural machinery operator, etc.), but above all for designers of modern starting systems for combustion engines and service personnel. The obtained results of testing the electrical parameters of the combustion engine during start-up may be helpful in designing new drive systems supported by a compression–ignition combustion engine.

Assessment of performance, combustion, and emission characteristics of single cylinder diesel engine fuelled by pyrolysis oil + CeO2 nanoparticles and 1-butanol blends

This experimental work focused on trials on diesel engines using Pyrolysis blends. The novelty in this work is the addition of cerium oxide additives with 1-butanol as an ignitor. The blends used were D100, 90D7WPO3B + 25 ppm CeO2, 85D10WPO5B + 50 ppm CeO2, 80D13WPO7 + 75 ppm CeO2 and 100WPO + 100 ppm CeO2. The results were outstanding as BTE is good for the fuel 90D7WPO3B + 25 ppm CeO2 by 36.2%, which is 12.25% greater than diesel, BSFC is better for the blend 90D7WPO3B + 25 ppm CeO2 by 0.22 kg/kWh, and maximum in-cylinder pressure obtained for 90D7WPO3B + 25 ppm CeO2 blend rated as 66.45bar; and maximum HRR is obtained for 85D10WPO5B + 50 ppm CeO2 blends by 84 J/ deg CA, BSEC of 85D10WPO5B + 50 ppm CeO2 blend is lower next only to diesel by 12.5 KJ/kWh, NOX emission minimum for 100WPO + 100 ppm CeO2 blends rate of 12 g/kWh, 14.2% lower than diesel, and lowest CO is attained for blend 80D13WPO7 + 75 ppm CeO2 blends at a rate of 0.8 g/kWh, 27.7% less than diesel, CO2 is minimum for blend 80D13WPO7 + 75 ppm CeO2 rate of 5 g/kWh; 18.03% less than diesel and HC is minimum for blend 100WPO + 100 ppm CeO2 blend rate of 0.18 kg/kWh; Which is 40% lower than diesel.

Investigation of the performance and emissions of a diesel engine fuelled with bio-oil generated through microwave-assisted pyrolysis of a blend of hazelnut, walnut, and polyethylene terephthalate waste

New and renewable energy sources are the most important issue nowadays. Bio-oil which can replace fossil fuel is an alternative source of energy. In this study, the performance effects and emissions of bio-oil produced by microwave-assisted pyrolysis system (MAP) from the walnut shell (WS), hazelnut shell (HS), and polyethylene terephthalate (PET) waste mixtures on a single-cylinder diesel engine were investigated. For this purpose, WS, HS, and PET wastes were mixed in two different proportions and converted into pyrolytic oil in the MAP system at 700 watts of microwave power and a 30-minute retention time. Produced pyrolytic oils were converted into bio-oil as S1 (46.25% WS + 46.25% HS + 2.5% PET) and S2 (43.75% WS + 43.75% HS + 7.5% PET) through a 3-stage basic upgrading steps. Experimental results showed that MAP of mixed WS, HS, and PET resulted in high hydrocarbon content bio-oil. In the engine experiments, bio-oil was mixed with diesel at 10%, 20%, and 30% ratios by volume and used in a diesel engine at different Brake Mean Effective Pressure (BMEP) (1.4, 2, 2.7, and 3.4 bar). Engine performance has been found to be comparable to diesel at low blend percentages. At 3.4 bar BMEP, while the brake-specific fuel consumption (BSFC) of diesel was 712 g/kWh, it was obtained as 832 and 804 g/kWh at S1 and S2, respectively. However, when the emissions were evaluated in general, it was determined that the emission values increased with increasing bio-oil/diesel blend ratios due to the high viscosity, higher density, and low cetane number of bio-oil compared to diesel.

Water-in-Biodiesel Emulsion with Hydroxy (HHO) Gas Fuel Enrichment for Single-Cylinder Diesel Engine Application

The rising issue of the depletion of fossil fuels opened a new pathway to seek alternative fuels to fulfil World Sustainable Development Goals (SDG). The application of high-blending biodiesel is possible however, it causes the diesel engine to perform poorly due to high viscosity, high fuel consumption, and increased NOx emission. To comply with the strict regulation, the idea of combining alternative fuels of high blending biodiesel, water-in-biodiesel emulsion, and hydrogen is seen as possible to solve the issue of each alternative fuel. Therefore, this study focused on the effect of high blending of biodiesel, water-in-biodiesel emulsion with hydroxy (HHO) enrichment in single-cylinder diesel engines on engine performance and exhaust emission. The fuel tested for this study are B10, B50, and an emulsion of B50 with the addition of HHO known as B50H and tested on engine speeds of 2400rpm under various loading conditions of 1kW, 2kW, 3kW, and 4kW. The result showed the B50H showed improvement in Fuel Consumption (FC) by 4%, 5% for Brake Thermal Efficiency (BTE), and reduced Nitrogen oxide (NOx) by 23% compared to B10 fuel. Thus, the combination of high blending of biodiesel, water-in-biodiesel emulsion, and HHO gas successfully improved diesel engine performance and reduced harmful exhaust emissions to promote clean and renewable energy, without depending on current diesel fuel.

Investigations on a Spark Ignition Engine, Part II: Impact of Hydrogen Addition and Compression Ratio on a Biogas-Fuelled Engine

Performance, emissions and combustion were studied using a spark ignition engine modified from a single-cylinder diesel engine with varying compression ratios and hydrogen addition. When the compression ratio increases, there is a slight increase in brake power and thermal efficiency. There is a small increase in brake power and brake thermal efficiency when the compression ratio is above 13:1. Increased emissions of nitric oxide, hydrocarbon, and carbon monoxide were observed at compression ratios above 13:1. Leaner mixtures, brake power and brake thermal efficiency are lowered. Spark timing is retarded as the compression ratio rises which results in high peak pressure and rate of heat release. At a compression ratio of 13:1, a small amount of hydrogen (15% on an energy basis) was added along with biogas. The lean limit of biogas combustion and the combustion rate are greatly increased by the addition of hydrogen. In addition, there was a rise in brake power and thermal efficiency. The levels of hydrocarbons were significantly reduced. Nitric oxide emissions did not rise as a result of the use of the retarded ignition timing. The effect of two throttle conditions on spark ignition engines using biogas as fuel is presented as Part I of this study.