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Effect of Hydrocarbon Molecular Structure on Diesel Exhaust Emissions Part 2: Effect of Branched and Ring Structures of Paraffins on Benzene and Soot Formation
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Abstract
The effect of the chemical reactivity of diesel fuel on PM formation was investigated using a flow reactor and a shock tube. Reaction products from the flow-reactor pyrolysis of the three diesel fuels used for the engine tests in Part 1(1) (“Base”, “Improved” and Swedish “Class-1”) were analyzed by gas chromatography. At 850C, Swedish “Class-1” fuel was found to produce the most PM precursors such as benzene and toluene among the three fuels, even though it contains very low amounts of aromatics. The chemical analyses described in Part 1 revealed that “Class-1” contains a large amount of branched and cyclic structures in the saturated hydrocarbon portion of the fuel. These results suggest that the presence of such branched and ring structures can increase exhaust PM emissions. This finding was confirmed by flow reactor experiments at 850 and 1000C with octane and hexane isomers which revealed that iso-and cycloparaffins produce more benzene than n-paraffins, both during pyrolysis and fuel-rich oxidation. With branched hexane isomers, the benzene amount increased with the increasing number of branches in the structure. The shock tube measurements on fuel-rich oxidation near 2000C showed that the soot formation yield increases in the order of n-hexane, 2-methylpentane, 2,2-dimethylbutane and cyclohexane. These results indicate that the specific molecular structures of the paraffinic components need to be considered as one of the diesel fuel properties closely related with PM formation.
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Authors
- Yoshiki Takatori - Toyota Central R&D Labs., Inc.
- Yoshiyuki Mandokoro - Toyota Central R&D Labs., Inc.
- Kazuhiro Akihama - Toyota Central R&D Labs., Inc.
- Kiyomi Nakakita - Toyota Central R&D Labs., Inc.
- Yukihiro Tsukasaki - Toyota Motor Corp.
- Satoshi Iguchi - Toyota Motor Corp.
- Lisa I. Yeh - Exxon Research & Engineering Co.
- Anthony M. Dean - Exxon Research & Engineering Co.
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Citation
Takatori, Y., Mandokoro, Y., Akihama, K., Nakakita, K. et al., "Effect of Hydrocarbon Molecular Structure on Diesel Exhaust Emissions Part 2: Effect of Branched and Ring Structures of Paraffins on Benzene and Soot Formation," SAE Technical Paper 982495, 1998, https://doi.org/10.4271/982495.Also In
References
- Nakakita, K. Takasu, S. Ban, H. Ogawa, T. Tsukasaki, Y. Yeh, L.I. “Effect of Hydrocarbon Molecular Structure on Diesel Exhaust Emissions -Part 1: Comparison of Combustion and Exhaust Emission Characteristics among Representative Diesel Fuels” 1998 SAE Fall Meeting
- Kobayashi, S. Nakajima, T. Hori, M. “Effect of Fuel Properties on Diesel Exhaust Emissions” SAE Paper, No. 945121 1994
- Tsurutani, K. Fujimoto, Y. Kumamoto, M. “The Effects of Fuel Properties and Oxygenates on Diesel Exhaust Emissions” SAE Paper, No. 952349 1995
- Ullman, T. Mason, R.L. Montalvo, D. “Effects of Fuel Aromatics, Cetane Improver on Emissions from a Prototype 1991 Diesel Engine” SAE Paper, No. 902171 1990
- Sienicki, E.J. Jass, R.E. Slodowdke, W.J. McCathy, C.I. Krodel, A.L. “Diesel Fuel Aromatic and Cetane Number Effects on Combustion and Emissions form a Prototype 1991 Diesel Engine” SAE Paper, No. 902172 1990
- Arai, M. “Impact of Changes in Fuel Properties and Lubrication Oil on Particulate Emissions and SOF” SAE Paper, No. 920556 1992
- Akasaka, Y. Sakurai, Y. “Effects of Fuel Properties on Exhaust Emission from DI Diesel Engine” JSME Journal Series B 63 1996 1091
- Nakakita, K. Kawamura, K. Ohsawa, K. Takahashi, T. Watanabe, S. “A Study on Mechanisims of Diesel NO X Formation and Soot Reduction under High-Pressure Fuel Injection” Transactions of JSAE 24 1 1993 5
- Frederick, W. Howard, J.B. Longwell, J.P. “The Behavior of Polycyclic Aromatic Hydrocarbons during the Early Stages of Soot Formation” Proc. 22nd Symp. (Int.) Combust. 1988 323
- Frenklach, M. Warnatz, J. “Detailed Modeling of PAH profiles in a Sooting Low-Pressure Acetylene Flame” Combust. Sci. Tech. 51 1987 265
- Graham, S.C. Homer, J.B. Rosenfeld, J.L.J. “The formation and coagulation of soot aerosols generated by the pyrolysis of aromatic hydrocarbons” Proc. R. Soc. 344 259 1975 259
- Frenklach, M. Wang, H. “Detailed Mechanism and Modeling of Soot Particle Formation” Soot Formation in Combustion 1994 165 Springer-Verlag
- Tan, Y. Dagaut, P. Cathonnet, M. Boettner J. C. “Acetylene Oxidation in a JSR From 1 to 10 Atm and Comprehensive Kinetic Modeling” Combust. Sci. Tech. 102 1994 21
- Miller, J. A. Melius, C. F. “Kinetic and Thermodynamic Issues in the Formation of Aromatic Compounds in Flames of Aliphatic Fuels” Combust. Flame 91 1992 21
- Westmoreland, P. R. Dean, A. M. Howard, J. B. Longwell, J. P. “Forming Benzene in Flames by Chemically Activated Isomerization” J. Phys. Chem. 93 1989 8171