Effect of Hydrocarbon Molecular Structure in Diesel Fuel on In-Cylinder Soot Formation and Exhaust Emissions

2003 ◽  
Author(s):  
Kiyomi Nakakita ◽  
Hitoshi Ban ◽  
Semon Takasu ◽  
Yoshihiro Hotta ◽  
Kazuhisa Inagaki ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Diesel Fuel ◽  
Soot Formation ◽  
Exhaust Emissions

Effect of Hydrocarbon Molecular Structure on Diesel Exhaust Emissions Part 2: Effect of Branched and Ring Structures of Paraffins on Benzene and Soot Formation

1998 ◽  
Author(s):  
Yoshiki Takatori ◽  
Yoshiyuki Mandokoro ◽  
Kazuhiro Akihama ◽  
Kiyomi Nakakita ◽  
Yukihiro Tsukasaki ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Diesel Exhaust ◽  
Soot Formation ◽  
Exhaust Emissions ◽  
Ring Structures

Effect of the hydrocarbon molecular structure in diesel fuel on the in-cylinder soot formation and exhaust emissions

2005 ◽  
Vol 6 (3) ◽  
pp. 187-205 ◽  
Author(s):  
K Nakakita ◽  
K Akihama ◽  
W Weissman ◽  
J T Farrell
Keyword(s):  
Molecular Structure ◽  
Diesel Fuel ◽  
Exhaust Emissions ◽  
Combustion Characteristics ◽  
Unexpected Result ◽  
Single Cylinder ◽  
Soot Precursors ◽  
Class 1 ◽  
Fuel Effects ◽  
Load Conditions

Evaluations of diesel fuel effects on combustion and exhaust emissions in single-cylinder direct-injection diesel engines led to the unexpected result that a Swedish ‘class 1’ fuel generated more particulate matter (PM) than a fuel denoted ‘improved’, even though ‘class 1’ fuel had much lower distillation temperatures, aromatic concentration, sulphur level, and density than the ‘improved’ fuel. Little differences were observed in the combustion characteristics between these fuels, but detailed compositional analyses showed that ‘class 1’ fuel contains higher levels of cyclic and/or branched paraffins. Subsequent investigations in a laboratory flow reactor showed that ‘class 1’ fuel produces more soot precursors such as benzene and acetylene than the ‘improved’ fuel. In addition, experiments in a low-pressure laminar flame apparatus and shock tube with model (single-molecule) paraffin fuels showed that isoparaffins and cycloparaffins generate more soot precursors and soot than n-paraffins do. These results strongly suggested that the effect of molecular structure on exhaust PM formation should be more carefully examined. Therefore, a new series of investigations were performed to examine exhaust emissions and combustion characteristics in single-cylinder engines, with well-characterized test fuels having carefully controlled molecular composition and conventional distillation characteristics and cetane numbers (CNs). These investigations revealed the following. Firstly, under low and medium loads, cycloparaffins (naphthenes) have a higher PM formation tendency than isoparaffins and n-paraffins. Under high-load conditions, however, the paraffin molecular structure has a very small effect. Secondly, a highly n-paraffinic fuel does not yield PM reductions as high as expected, due to its high CN and corresponding shorter ignition lag, which initiates combustion under a state of insufficient fuel-air mixing. This finding was corroborated by laser-induced incandescence analyses. Thirdly, the lowest PM emissions were observed with a paraffinic fuel containing 55 per cent isoparaffins and 39 per cent n-paraffins. Fourthly, aromatics give higher soot and PM levels than paraffins do at high and medium load conditions. Smaller differences are observed at lower speeds and loads. Fifthly, the best fit to the PM emissions was obtained with an equation containing the regression variables CN, aromatic rings, and naphthene rings. This expression of the fuel effects in chemical terms allows well-to-wheel analyses of refining and vehicle impacts resulting from molecularly based fuel changes.

Effects of Fuel Species on Soot Formation in Laminar Counterflow: Comparison Between Diesel Fuel and Palm Methyl Ester as an Alternative Fuel

2011 ◽  
Author(s):  
Jun Hayashi ◽  
Fumiteru Akamatsu ◽  
Nozomu Hashimoto ◽  
Hiroyuki Nishida
Keyword(s):  
Molecular Structure ◽  
Oxygen Content ◽  
Diesel Fuel ◽  
Volume Fraction ◽  
Soot Formation ◽  
Soot Volume Fraction ◽  
Alternative Fuel ◽  
Chain Structure ◽  
Spray Flame ◽  
Palm Methyl Ester

Spray combustion of liquid fuel is utilized in many combustion systems. There are, however, still remained-problems. One of the most important problems is to clarify the combustion characteristics, especially soot formation process. At the same time, the liquid fuel of biomass is getting a lot of attention as an alternative fuel in recent years from the viewpoint of the environmental issues and the exhaustion of fossil fuels. In this study, we focused on the palm methyl ester (PME), which has a large production capacity and oxygen content in its molecular structure. The aim of this study is to clarify the combustion characteristics and soot formation characteristics of PME spray flame for the effective utilization to the conventional combustion systems as the alternative fuel. In order to clarify the soot formation characteristics of PME spray flame, measurements of Sauter mean diameter (SMD) and droplet size distribution by using phase Doppler anemometry (PDA) and measurement of two dimensional soot formation characteristics by using Laser Induced Incandescence technique (LII) are conducted in laminar counterflow field. In addition, since the PME has a normal chain structure and oxygen content in its molecular structure, it needs to clarify effect of the oxygen content and normal chain structure. The comparison with diesel fuel and n-dodecane are also conducted. Results of LII measurements show that the PME and the n-dodecane spray have similar spray flame structures, time-averaged soot volume fraction and instantaneous structure of soot formation while PME has the oxygen content in the molecular structure. On the other hand, the time-averaged soot volume fraction and soot formation area of PME are smaller than those of diesel fuel. It is because the diesel fuel has some components with the aromatic ring. These results indicate that it is not the oxygen content but the normal chain structure in the PME play an essential role in influencing soot formation characteristics.

Investigation of Soot Formation During Partial Oxidation of Diesel Fuel

2007 ◽  
Vol 30 (6) ◽  
pp. 782-789 ◽  
Author(s):  
K. Roth ◽  
S. Wirtz ◽  
V. Scherer ◽  
W. Nastoll
Keyword(s):  
Partial Oxidation ◽  
Diesel Fuel ◽  
Soot Formation

The Effect of Hydrotreatment of Diesel Fuel Derived from Canadian Tar Sands on Particulate Exhaust Emissions

1982 ◽  
Author(s):  
David L. Hilden ◽  
Stephen P. Bergin ◽  
Harvey A. Burley ◽  
Ronald D. Tharby ◽  
Ian P. Fisher
Keyword(s):  
Diesel Fuel ◽  
Exhaust Emissions ◽  
Tar Sands

scholarly journals THE EFFECT OF DIESEL-BIODIESEL BLENDS ON THE PERFORMANCE AND EXHAUST EMISSIONS OF A DIRECT INJECTION OFF-ROAD DIESEL ENGINE

Transport ◽  
2014 ◽  
Vol 29 (4) ◽  
pp. 440-448 ◽  
Author(s):  
Tomas Mickevičius ◽  
Stasys Slavinskas ◽  
Slawomir Wierzbicki ◽  
Kamil Duda
Keyword(s):  
Diesel Engine ◽  
Diesel Fuel ◽  
Direct Injection ◽  
Engine Performance ◽  
Exhaust Emissions ◽  
Bench Test ◽  
Maximum Pressure ◽  
Cylinder Pressure ◽  
Biodiesel Blends ◽  
Performance And Emission

This paper presents a comparative analysis of the diesel engine performance and emission characteristics, when operating on diesel fuel and various diesel-biodiesel (B10, B20, B40, B60) blends, at various loads and engine speeds. The experimental tests were performed on a four-stroke, four-cylinder, direct injection, naturally aspirated, 60 kW diesel engine D-243. The in-cylinder pressure data was analysed to determine the ignition delay, the Heat Release Rate (HRR), maximum in-cylinder pressure and maximum pressure gradients. The influence of diesel-biodiesel blends on the Brake Specific Fuel Consumption (bsfc) and exhaust emissions was also investigated. The bench test results showed that when the engine running on blends B60 at full engine load and rated speed, the autoignition delay was 13.5% longer, in comparison with mineral diesel. Maximum cylinder pressure decreased about 1–2% when the amount of Rapeseed Methyl Ester (RME) expanded in the diesel fuel when operating at full load and 1400 min–1 speed. At rated mode, the minimum bsfc increased, when operating on biofuel blends compared to mineral diesel. The maximum brake thermal efficiency sustained at the levels from 0.3% to 6.5% lower in comparison with mineral diesel operating at full (100%) load. When the engine was running at maximum torque mode using diesel – RME fuel blends B10, B20, B40 and B60 the total emissions of nitrogen oxides decreased. At full and moderate load, the emission of carbon monoxide significantly raised as the amount of RME in fuel increased.

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