A Comprehensive Review on Low-Temperature Combustion Technologies for Emission Reduction in Diesel Engines

Diesel engines are lean burn engines; hence CO and HC emissions in the exhaust are less likely to occur in substantial amounts. The emissions of serious concern in compression ignition engines are particulate matter and nitrogen oxides because of elevated temperature conditions of combustion. Hence the researchers have strived continuously to lower down the temperature of combustion in order to bring down the emissions from CI engines. This has been tried through premixed charge compression ignition, homogeneous charge compression ignition (HCCI), gasoline compression ignition and reactivity controlled compression ignition (RCCI). In this study, an attempt has been made to critically review the literature on low-temperature combustion conditions using various conventional and alternative fuels. The problems and challenges augmented with the strategies have also been described. Water-in-diesel emulsion technology has been discussed in detail. Most of the authors agree over the positive outcomes of water-diesel emulsion for both performance and emissions simultaneously.

PENGARUH ARANG KAYU ULIN SEBAGAI CATALYTIC CONVERTER TERHADAP EMISI GAS BUANG DAN KONSUMSI BAHAN BAKAR PADA MESIN TOYOTA KIJANG 5K

Catalytic Converter adalah pengubah (modifier) yang menggunakan media yang memiliki katalis, dimana media tersebut diharapkan dapat membantu atau mempercepat proses perubahan zat (reaksi kimia) sehingga gas seperti CO dapat dioksidasi menjadi CO2, media katalis kimia pada suhu tertentu, tanpa perubahan atau penggunaan oleh reaksi itu sendiri. Catalytic converter berbahan arang kayu ulin untuk emisi gas buang dan konsumsi bahan bakar. Jenis penelitian ini adalah penelitian eksperimen. Pengujian yang dilakukan pada penelitian ini ada 2 yaitu knalpot tanpa catalytic converter dan knalpot dengan catalytic converter berbahan arang kayu ulin dengan variasi rpm 1500, 2500, 3500. Pengujian emisi gas buang menggunakan alat yang disebut gas analyzer. Berdasarkan hasil penelitian dapat disimpulkan bahwa catalytic converter berbahan arang kayu ulin dengan diameter lubang 20 mm mampu mereduksi emisi CO dengan reduksi sebesar 52,23%, dan emisi HC lubang berdiameter 20 mm dengan jumlah 85,63. Catalytic Converter is a converter (modifier)that uses media that has a catalyst, where the media is expected to help or accelerate the process of changing substances (chemical reactions) so that gases such as CO can be oxidized to CO2, chemical catalyst media at a certain temperature, without change or use by the reaction itself. Catalytic converters made from ironwood charcoal to exhaust emissions and fuel consumption. This type of research is experimental research. There are 2 tests of this research, namely exhaust without catalytic converter and exhaust with catalytic converter made from ironwood charcoal with variations in rpm 1500, 2500, 3500. Examination of exhaust emissions using a device called a gas analyzer. Based on the results of the study it can be concluded that catalytic converters made from ironwood charcoal with a hole diameter of 20 mm were able to reduce CO emissions with a reduction of 52.23%, and HC emissions of a hole diameter of 20 mm with an amount of 85.63,

Economy and emission characteristics of the optimal dilution strategy in lean combustion based on GDI gasoline engine equipped with prechamber

EGR and excess-air dilution have been investigated in a 1.5 L four cylinders gasoline direct injection (GDI) turbocharged engine equipped with prechamber. The influences of the two different dilution technologies on the engine performance are explored. The results show that at 2400 rpm and 12 bar, EGR dilution can adopt more aggressive ignition advanced angle to achieve optimal combustion phasing. However, excess-air dilution has greater fuel economy than that of EGR dilution owing to larger in-cylinder polytropic exponent. As for prechamber, when dilution ratio is greater than 37.1%, the combustion phase is advanced, resulting in fuel economy improving. Meanwhile, only when the dilution ratio is under 36.2%, the HC emissions of excess-air dilution are lower than the original engine. With the increase of dilution ratio, the CO emissions decrease continuously. The NOX emissions of both dilution technologies are 11% of those of the original engine. Excess-air dilution has better fuel economy and very low CO emissions. EGR dilution can effectively reduce NOX emissions, but increase HC emissions. Compared with spark plug ignition, the pre chamber ignition has lower HC, CO emissions, and higher NO emissions. At part load, the pre-chamber ignition reduces NOX emissions to 49 ppm.

Experimental investigation on n-butanol/methyl oleate dual fuel RCCI combustion in a single cylinder engine at high-load condition

Reactivity controlled compression ignition (RCCI) engines have a high thermal efficiency as well as low emissions of soot and nitrogen oxides (NOx). However, there is a conflict between combustion stability and harmful emissions at high engine load. Therefore, this work presented a novel approach for regulating n-butanol/methyl oleate dual fuel RCCI at high engine load in attaining lower pollutant emissions while maintaining stable combustion and avoiding excessive in-cylinder pressure. The tests were conducted on a single cylinder engine under rated speed and 90% full load. In this study, n-butanol was selected as a low-reactivity fuel for port injection, and n-butanol/methyl oleate blended fuel was used for in-cylinder direct injection. Combustion and emission characteristics of the engine were first investigated with varied ratios of n-butanol port injection (PFI) and direct injection (DI). Results showed that as the ratio of n-butanol PFI and DI rose, the peak cylinder pressure and heat release rate increased, while NOx and soot emissions reduced, and carbon monoxide (CO) and hydrocarbon (HC) emissions increased under most test conditions. When RNBPI = 40% and RNBDI = 20%, the soot and NOx emissions of the engine were near the lowest values of all test conditions, yet the peak in-cylinder pressure and fuel consumption could not increase significantly. Therefore, the possibility of optimizing the combustion process and lowering emissions by adjusting the pilot injection strategy was investigated utilizing these fuel injection ratios. The results revealed that with an appropriate pilot injection ratio and interval, the peak in-cylinder pressure and NOx emission were definitely reduced, while soot, CO, and HC emissions did not significantly increase.

Performance of Common Rail Direct Injection (CRDi) Engine Using Ceiba Pentandra Biodiesel and Hydrogen Fuel Combination

An existing diesel engine was fitted with a common rail direct injection (CRDi) facility to inject fuel at higher pressure in CRDi mode. In the current work, rotating blades were incorporated in the piston cavity to enhance turbulence. Pilot fuels used are diesel and biodiesel of Ceiba pentandra oil (BCPO) with hydrogen supply during the suction stroke. Performance evaluation and emission tests for CRDi mode were carried out under different loading conditions. In the first part of the work, maximum possible hydrogen substitution without knocking was reported at an injection timing of 15° before top dead center (bTDC). In the second part of the work, fuel injection pressure (IP) was varied with maximum hydrogen fuel substitution. Then, in the third part of the work, exhaust gas recirculation (EGR), was varied to study the nitrogen oxides (NOx) generated. At 900 bar, HC emissions in the CRDi engine were reduced by 18.5% and CO emissions were reduced by 17% relative to the CI mode. NOx emissions from the CRDi engine were decreased by 28% relative to the CI engine mode. At 20%, EGR lowered the BTE by 14.2% and reduced hydrocarbons, nitrogen oxide and carbon monoxide by 6.3%, 30.5% and 9%, respectively, compared to the CI mode of operation.

Vehicle Emissions and Air Quality: The Early Years (1940s–1950s)

During the 1940s, an unusual form of air pollution was experienced in the Los Angeles (LA) area of Southern California. Referred to as LA smog, this pollution differed from previously known air pollution with respect to its temporal patterns (daytime formation and nighttime dissipation), eye irritation, high oxidant levels, and plant damage. Early laboratory and field experimentation discovered the photochemical origins of LA smog. Though mechanistic understanding was incomplete, it was determined that hydrocarbon (HC) compounds in the atmosphere participate in smog formation, enabling build-up of higher ozone concentrations than would otherwise occur. It being a significant source, there was great interest in characterizing and controlling HC emissions from motor vehicles. Considerable work was done in the 1940s and 1950s to understand how emissions varied with vehicle operating conditions and deterioration of engine components. During this time, procedures were developed (and improved) to sample and quantify vehicle emissions. Besides exhaust, HC emissions from crankcase blowby, carburetor evaporation, and fuel tank losses were measured and characterized. Initial versions of both catalytic and non-catalytic exhaust after-treatment systems were developed. The knowledge gained from this pre-1960 work laid the foundation for many advancements that reduced vehicle emissions and improved air quality during subsequent decades.

Effect of Aluminium Oxide Nano Additive on Diesel along with Gasoline Fumigation in Single Cylinder Diesel Engine

The present investigation mainly focuses on overcoming the limitations of gasoline fumigation (GF) in diesel engines by adding up nano fuel additives. Experiments are conducted to ascertain the engine working characteristics in a single-cylinder, four-stroke diesel engine using aluminum oxide (Al2O3) nano additives blended diesel as the main injection fuel along with GF as an inducted fuel. GF was achieved by controlling the electronic injector fitted at the intake manifold using open ECU software. Fuel map for GF was determined based on experiments with three divergent fumigation rates of 10%, 20%, and 30% based on energy consumption and optimized using the design of experiments. The optimization results showed 10% fumigation resulted in better performance and emission characteristics and it is selected for this present investigation. Fumigation results showed a decrease in brake thermal efficiency (BTE) at low and medium loads; increase at high loads.The two different mass fractions of 25 ppm and 50 ppm Al2O3 nano liquid are blended with diesel. Compared to GF with diesel, GF along with 25 and 50ppm Al2O3 nano additives blended diesel showed an increased BTE, maximum in-cylinder pressure, cumulative heat release rate; and reduced smoke opacity, CO, and unburned HC emissions at overall operating conditions. As the dosage level of Al2O3 increases from 25 to 50 ppm results in further enhancement of all working parameters except NOx emission. Finally, the addition of an Al2O3 nano additive is a suitable solution to overcome the limitations of GF in the CI engine.

Performance and Emissions of a Spark Ignition Engine Fueled with Water-in-Gasoline Emulsion Produced through Micro-Channels Emulsification

This paper presents an experimental study investigating the effects of water-in-gasoline emulsion (WiGE) on the performance and emissions of a turbocharged PFI spark-ignition engine. The emulsions were produced through a micro-channels emulsifier, potentially capable to work inline, without addition of surfactants. Measurements were performed at a 3000 rpm speed and net Indicated Mean Effective Pressure (IMEP) of 16 bar: the engine point representative of commercial ECU map was chosen as reference. In this condition, the engine, fueled with gasoline, runs overfueled (λ = 0.9) to preserve the integrity of the turbocharger from excessive temperature, and the spark timing corresponds to the knock limit. Starting from the reference point, two different water contents in emulsion were tested, 10% and 20% by volume, respectively. For each selected emulsion, at λ = 0.9, the spark timing was advanced from the reference point value to the new knock limit, controlling the IMEP at a constant level. Further, the cooling effect of water evaporation in WiGE allowed it to work at stoichiometric condition, with evident benefits on the fuel economy. Main outcomes highlight fuel consumption improvements of about 7% under stoichiometric mixture and optimized spark timing, while avoiding an excessive increase in turbine thermal stress. Emulsions induce a slight worsening in the HC emissions, arising from the relative impact on combustion development. On the other hand, at stoichiometric condition, HC and CO emissions drop with a corresponding increase in NO.

Effect of the Using of Racing Exhaust with variation Soundproofing Material Against Exhaust Emissions and Noise on 4 Stroke Motorcycle

This study discusses the effect of using a racing exhaust with asbestos and stainless steel-based filters. The purpose of this study is to find out how big the role of racing exhaust filters in reducing noise and exhaust emissions. This study uses an experimental method with the static comparison design. The object of this research is Honda Beat injection motorcycle 2017. The data from this study were taken from testing standard exhaust, stainless steel, and asbestos. Based on the research that has been done, it can be concluded that the use of stainless steel-based filters is effective in reducing HC emissions compared to standard exhausts and racing exhausts with asbestos filters, stainless steel filters are also effective in reducing noise by 4.4% compared to exhausts with asbestos filters. Penelitian ini membahas tentang pengaruh dari pemakaian knalpot racing dengan saringan berbahan dasar asbes dan stainless steel. Tujuan dari penelitian ini yaitu mengetahui seberapa besar peranan saringan knalpot racing dalam mereduksi kebisingan dan emisi gas buang yang dihasilkan. Penelitian ini menggunakan metode eksperimen dengan desain the static comparison design. Objek dari penelitian ini adalah sepeda motor Honda Beat injeksi tahun 2017. Data dari penelitian ini diambil dari pengujian knalpot standar, stainless steel, dan asbes. Berdasarkan hasil penelitian disimpulkan bahwa penggunaan saringan berbahan dasar stainless steel efektif mereduksi emisi HC dibanding knalpot standar dan knalpot racing dengan saringan asbes, saringan stainless steel juga efektif mereduksi kebisingan sebesar 4,4% dibandingkan kanlpot dengan saringan asbes.