Effect of Octane Number on Performance and Exhaust Emissions of an SI Engine

2020 ◽  
Vol 38 (4A) ◽  
pp. 574-585
Author(s):  
Noor H. Athafah ◽  
Adei M. Salih

Spark ignition engines are very popular engines that they are running millions of vehicles all over the world. This engine emits many harmful pollutants, such as CO, UHC, and NOX. In this paper, the impact of gasoline octane number on the engine performance and exhaust emissions was studied. In the tests, four-cylinder, four-stroke engine, and two variable octane numbers (RON83 and 94.5) were used. The engine was run at different engine speeds and loads. The results from the experimental study indicated that the brake specific fuel consumption (bsfc) of RON94.5 was higher than RON83 by 13.93%, while the brake thermal efficiency (ƞbth) was higher for RON83 compared to RON94.5 by 12.31%. The emitted emissions for the tested fuels were high when RON83 was used compared to RON94.5 by 65.52%, 49.11%, and 57.33% for CO, UHC, and NOX, respectively.

2021 ◽  
Vol 9 (4A) ◽  
Author(s):  
İlker Örs ◽  
◽  
Murat Ciniviz ◽  
Bahar Sayin Kul ◽  
Ali Kahraman ◽  
...  

In this study, it was aimed to investigate the effects of a diesel-biodiesel blend (B20) and a diesel-biodiesel-bioethanol blend (BE5) on combustion parameters in addition to engine performance and exhaust emissions compared with diesel fuel. Parameters included in the evaluation was brake specific fuel consumption, brake thermal efficiency, CO, CO2, HC, NOx, smoke opacity emissions and finally cylinder pressure, heat release rate, ignition delay, some key points of the combustion phases such as start of ignition, start of combustion, CA50 and CA90 and combustion duration. Engine tests were conducted at different injection pressures of 170 bar, 190 bar, which is the original injection pressure, and 220 bar by the engine being loaded by 25, 50, 75 and 100% for the assessment of engine performance and exhaust emissions. For combustion evaluation, the data obtained at 1400 rpm, maximum torque-speed, and 2800 rpm, maximum power-speed were used, while the injection pressures were set to 170, 190 and 220 bar under full load condition. According to test results, the better performance characteristics, exhaust emissions and combustion behaviour of engine were obtained with the use of BE5 at high injection pressure. So, BE5 fuel improved brake specific fuel consumption by about 7% and brake thermal efficiency by about 6% compared to B20. In addition, while the emission values of BE5 gave better results than diesel fuel, it reduced the NOx and smoke emissions of B20 by approximately 1.4% and 6.4% respectively. Moreover, it has achieved a reduction in smoke emission of up to 45% compared to diesel fuel.


2021 ◽  
Vol 18 (22) ◽  
pp. 451
Author(s):  
Ekkachai Sutheerasak ◽  
Charoen Chinwanitcharoen ◽  
Sathaporn Chuepeng

Biofuels are an alternative fuel currently being developed to reduce the diesel-engine environmental impact. The release of carbon dioxide (CO2), nitric oxide (NO) and black smoke (BS) becomes an issue derived from diesel engines even in lean-mixture combustion causing an adverse effect to human health. The main aim of the research study is to present the use of biofuels, a mixture of diesel and 10 % palm oil ethyl ester (PEE10) and PEE10 blended with bioethanol from 5 to 20 %, compared with conventional diesel fuel. The biofuels were run on a high-speed direct injection diesel engine at a constant speed of 3,000 rpm under various loads. The use of PEE10 resulted in brake thermal efficiency (BTE) reduction by 2 % and brake specific fuel consumption (BSFC) incrementation by 8 %, but the exhaust emissions were lower than diesel, except for CO2 and NO. However, PEE10 engine performance was better and exhaust gas emissions were lower for both pollutants than diesel mixed with 10 % bioethanol. The investigation of PEE10 with increasing bioethanol revealed that the use of PEE10 blended with 5 % bioethanol (PEE10E5) can improve engine performance, while the BTE and BSFC were close to that of diesel, and exhaust emissions, especially CO2, NO and BS reduced. Moreover, BTE from PEE10E5 fueling increased by 2 % but BSFC was subtle increased, compared to PEE10. On the other hand, the increasing bioethanol from 10 to 20 % in PEE10 led to the more reduction in engine performance, but the engine pollutants were also continuously decreased. Specifically, the blend of PEE10 and 20 % bioethanol indicates that CO2, NO and BS were reduced by 10, 15 and 33 %, respectively, compared to diesel fuel. HIGHLIGHTS A mixture of diesel and 10 % palm oil ethyl ester (PEE10) has less exhaust emissions than diesel blended with 10 % palm oil methyl ester (PME10) PEE10 blended with 5 % bioethanol can improve engine performance, while the brake thermal efficiency and brake specific fuel consumption are close to that of diesel and PME10 The increasing bioethanol from 10 to 20 % in PEE10 leads to the more reduction in engine performance, but the engine pollutants, especially carbon dioxide, nitric oxide and black smoke, are also continuously decreased GRAPHICAL ABSTRACT


2019 ◽  
Vol 8 (4) ◽  
pp. 10953-10956

Experimental investigations were conducted to study the feasibility of alcohol (Ethanol) and its blends with petrol at varying proportions from 0 to 100% in a single cylinder diesel engine converted to operate in spark ignited (SI) mode. Performance and emission characteristics of the SI engine was evaluated and compared with base line petrol operation. Addition of ethanol to petrol provides lower carbon monoxide (CO), hydrocarbon (HC) and nitric oxide (NOx ) emissions. Among all blend ratio performance results E75 shows overall improved engine performance with increased brake thermal efficiency (BTE) with lower emissions.


2018 ◽  
Vol 22 (1) ◽  
pp. 55-68 ◽  
Author(s):  
Abdulvahap Cakmak ◽  
Murat Kapusuz ◽  
Orkhan Ganiyev ◽  
Hakan Ozcan

Abstract - The objective of this paper is to investigate the use of methyl acetate as oxygenated fuel blending for base gasoline in SI engine. The effects of methyl acetate on engine performance parameters (brake specific fuel consumption, brake thermal efficiency and energy consumption rate) and exhaust emissions (CO, HC, CO2 and NOx) of SI engine have been experimentally investigated. Engine experiments were conducted on a single cylinder, water cooled, spark-ignition test engine at constant moderate speed; 1500 rpm for different loads; 104, 207, 311 and 414 kPa fuelling the engine with base gasoline, M5 (95 % base gasoline +5 % methyl acetate) and M10 (90 % base gasoline +10 % methyl acetate). The results showed that adding methyl acetate to base gasoline increases the brake specific fuel consumption while reducing the brake thermal efficiency of the engine. Furthermore, it was also observed that methyl acetate addition does not have a great effect on HC emissions, however, reduces CO and increases CO2 emissions. NOx results showed a striking increase in the level of NOx emissions with the addition of methyl acetate.


Author(s):  
M. V. S. Murali Krishna ◽  
Ch. Indira Priyadarsini ◽  
P. Ushasri ◽  
P. V. K. Murthy ◽  
D. Baswaraju

Investigations were carried out to evaluate the performance of two stroke and four stroke of single cylinder, spark ignition (SI) engines having copper coated engine [CCE, copper-(thickness, 300 μ)] coated on piston crown and inner side of cylinder head] provided with catalytic converter with sponge iron as catalyst with methanol blended gasoline (80% gasoline and 20% methanol by volume) and compared with conventional engine (CE) with pure gasoline operation. Performance parameters — brake thermal efficiency (BTE), exhaust gas temperature (EGT), volumetric efficiency and exhaust emissions of carbon monoxide (CO) and un-burnt hydrocarbon (UBHC) were determined with different values of brake mean effective pressure (BMEP) of the engine and compared with one over the other of two stroke and four stroke SI engine with different versions of the engine. Formaldehyde and acetaldehyde emissions were measured by 2, 4 dinitrophenyl hydrazine (2,4 DNPH) method at peak load operation of CE and CCE of two-stroke and four-stroke SI engine. The engine was provided with catalytic converter with sponge iron as catalyst. There was provision for injection of air into the catalytic converter. Brake thermal efficiency increased with methanol blended gasoline with both versions of the engine. CCE showed improvement in the performance when compared with CE with both test fuels. Four-stroke engine decreased exhaust emissions effectively in comparison with two-stroke engine with both versions of the engine. Catalytic converter with air injection significantly reduced exhaust emissions with different test fuels on both configurations of the engine.


Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 4034
Author(s):  
Paolo Iodice ◽  
Massimo Cardone

Among the alternative fuels existing for spark-ignition engines, ethanol is considered worldwide as an important renewable fuel when mixed with pure gasoline because of its favorable physicochemical properties. An in-depth and updated investigation on the issue of CO and HC engine out emissions related to use of ethanol/gasoline fuels in spark-ignition engines is therefore necessary. Starting from our experimental studies on engine out emissions of a last generation spark-ignition engine fueled with ethanol/gasoline fuels, the aim of this new investigation is to offer a complete literature review on the present state of ethanol combustion in last generation spark-ignition engines under real working conditions to clarify the possible change in CO and HC emissions. In the first section of this paper, a comparison between physicochemical properties of ethanol and gasoline is examined to assess the practicability of using ethanol as an alternative fuel for spark-ignition engines and to investigate the effect on engine out emissions and combustion efficiency. In the next section, this article focuses on the impact of ethanol/gasoline fuels on CO and HC formation. Many studies related to combustion characteristics and exhaust emissions in spark-ignition engines fueled with ethanol/gasoline fuels are thus discussed in detail. Most of these experimental investigations conclude that the addition of ethanol with gasoline fuel mixtures can really decrease the CO and HC exhaust emissions of last generation spark-ignition engines in several operating conditions.


Author(s):  
F. Daneshvar ◽  
N. Jahani ◽  
M. B. Shafii

In this experimental study, a four stroke diesel engine was conducted to investigate the effect of adding water-based ferrofluid to diesel fuel on engine performance. To our knowledge, Magnetic nanoparticles had not been used before. To this end, emulsified diesel fuels of 0, 0.4, and 0.8 water-based ferrofluid/Diesel ratios by volume were used as fuel. The ferrofluid used in this study was a handmade water-based ferrofluid prepared by the authors. The results show that adding water-based ferrofluid to diesel fuel has a perceptible effect on engine performance, increasing the brake thermal efficiency relatively up to 12%, and decreasing the brake specific fuel consumption relatively up to 11% as compared to diesel fuel. In addition, the results indicate that increasing ferrofluid concentration will magnify the results. Furthermore, it was found that magnetic nanoparticles can be collected at the engine exhaust using magnetic bar.


2015 ◽  
Vol 773-774 ◽  
pp. 430-434
Author(s):  
Azizul Mokhtar ◽  
Nazrul Atan ◽  
Najib Rahman ◽  
Amir Khalid

Bio-additive is biodegradable and produces less air pollution thus significant for replacing the limited fossil fuels and reducing threats to the environment from exhaust emissions and global warming. Instead, the bio-additives can remarkably improve the fuel economy SI engine while operating on all kinds of fuel. Some of the bio-additive has the ability to reduce the total CO2 emission from internal petrol engine. This review paper focuses to determine a new approach in potential of bio-additives blends operating with bio-petrol on performance and emissions of spark ignition engine. It is shown that the variant in bio-additives blending ratio and engine operational condition are reduced engine-out emissions and increased efficiency. It seems that the bio-additives can increase the maximum cylinder combustion pressure, improve exhaust emissions and largely reduce the friction coefficient. The review concludes that the additives usage in bio-petrol is inseparable for the better engine performance and emission control and further research is needed to develop bio-petrol specific additives.


2018 ◽  
Vol 21 (3) ◽  
pp. 368-373
Author(s):  
Kadhim Fadhil Nasir

The consequence of mixing pure ethanol with gasoline on the pollution and performance of SI engine are investigated experimentally in the existent study. The SI engine that employed in the experiment is a single cylinder four stroke. Analysis is carried out for engine operation parameter, CO2, CO and unburned HC productions. The measurements are recorded for several engine speeds from 1500 – 3000 rpm with load and ethanol addition of (0E, 10E, 20E, 30E, 40E, 50E,). The results displayed increasing in brake power, and brake thermal efficiency while the brake specific fuel consumption decreases when the ethanol- gasoline blends fuel increases. Also it was found that CO, HC, and CO2 concentrations decrease when the ethanol- gasoline increases. The best results obtained in the study is for the blend of E-50.


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