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Characterization of Exhaust Emissions in a SI Engine using E85 and Cooled EGR
Technical Paper
2009-01-1952
ISSN: 0148-7191, e-ISSN: 2688-3627
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English
Abstract
Gasoline-ethanol blends are being used or have been considered as a fuel for spark ignition engines. The motivation for using the blends varies in indifferent parts of the world and even in regions within a country. The increasing cost of gasoline, combined with regional tax incentives, is one of the reasons for increased interests in gasoline-ethanol blends in recent years in the U.S. Many vehicular engines are not designed to use a specific gasoline-ethanol blend. Rather, the engines have multi-blend capability, ranging from E0 to about E85. It is plausible that engine-out emissions will vary depending on the blend being used which may be further impacted by the level of EGR used with the blends. The present work was carried out to investigate engine out emissions when a vehicular spark-ignition engine was operated on E0 and E85 and different levels of EGR.
A 4-cylinder, 2.5 liter, PFI engine was used in the experimental investigation. The engine was operated at 1500 and 2100 rpm and brake mean effective pressure of 1.5 bar or 3.5 bar. The engine was operated at stoichiometric air-to-fuel ratio at controlled operating parameters. The mixture stoichiometry was monitored by a wide-range oxygen sensor calibrated for the fuels used in the study. Exhaust samples were analyzed for different emissions species using a FT-IR analyzer. Overall, E85 blend produced slightly lower levels of NOx than E0 (pure gasoline) but the difference was more noticeable at higher load and high EGR rates. But E85 produced much higher concentrations of acetalydehydes in engine exhaust than the gasoline fuel. The difference was more pronounced at lower engine load. Addition of EGR increased aldehyde levels even further.
The coefficient of variation in indicated mean effective pressure increased with an increase in EGR rate. Not much difference in the coefficient of variation between E85 and E0 was observed at higher engine load but there was a significant difference when the engine was operating at 1500 rpm and lower load. Similar trend was observed at higher EGR rates when the engine was operating at 2100 rpm. Low speed operation, combined with high EGR rates, lowers overall temperatures in the combustion chamber which favors acetalydehyde emissions. Depending on operating conditions, it may be necessary to limit EGR rates to keep COV in imep within limits when the engine is operated on E85.
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Varde, K. and Manoharan, N., "Characterization of Exhaust Emissions in a SI Engine using E85 and Cooled EGR," SAE Technical Paper 2009-01-1952, 2009, https://doi.org/10.4271/2009-01-1952.Also In
References
- Gielen Dolf Unander Fridtjof “Alternative Fuels: An Energy Technology Perspective,” 2005
- Gardiner D.P. et al. “Improving the Fuel Efficiency of Light-Duty Ethanol Vehicles – An Engine Dynamometer Study of Dedicated Engine Strategies,” SAE 1999-01-3568 1999
- Brusstar M. et al. “High Efficiency and Low Emissions from a Port-Injected Engine with Neat Alcohol Fuels,” SAE 2002-01-2743 2002
- Bechtold, R. Pullman, J. B. “Driving Cycle Economy, Emissions and Photochemical Reactivity using Alcohol Fuels and Gasoline,” SAE Paper 800260 1980
- “Alternative Fuel Vehicles,” 1996
- Benson, J. D., et al “Emissions with E85 and Gasoline in Flexible/Variable Fuel Vehicles,” SAE Paper 952508
- Varde, K. S. Clark, C. P. “A Comparison of Burn Characteristics and Exhaust Emissions from Off-Highway Engines Fueled on E0 and E85,” SAE Paper 2004-28-0045 2004
- Radwan M.S. “Performance and Knock Limits of Ethanol-Gasoline Blends in Spark-Ignited Engines,” SAE 850213 1985
- Dodge L.G. et al. “Development of an Ethanol-Fueled Ultra-Low Emissions Vehicle,” SAE 981358 1998
- American Coalition for Ethanol “Comparing Performance and Cost of Various Ethanol Blends and Standard Unleaded Gasoline,” 2005
- Varde, K. S. Jones, A. Knutsen, A. Mertz, D. Yu, P. “Exhaust Emissions and Energy Release Rates from a Controlled SI Engine Using Ethanol Blends,” J. Automobile Engineering, IMechE 221 933 941 2007
- Jacobson, M. Z. “Effects of Ethanol (E85) versus Gasoline Vehicles on Cancer and Mortality in the united States,” Env. Sc. Tech. 41 11 4150 4157 2007
- Metghalchi M. Keck J.C. “Burning Velocities of Mixtures of Air with Methanol, Isooctane and Indolene at High Pressure and Temperature, Combustion and Flame,” 48 191 210 1982
- Poulopoulos, S. G. Samaras, D. P. Philippopoulos, C. J. “Regulated and Unregulated Emissions from and Internal Combustion Engine Operating on Ethanol-Containing Fuels, Atmospheric Environment,” 35 4299 4406 2001
- Marinov, N. M “A Detailed Chemical Kinetic Model for High Temperature Ethanol Oxidation Int. J. Chemical Kinetics 31 3 183 220 1999
- Gardiner, W. C., Jr. Gas Phase Combustion Chemistry Springer Publisher NY 69 72 1999
- Brown, J. Tipper, C. F. H. “The Cool Flame Combustion of Ethanol,” Proc. Royal soc of London, Series A 312 399 415 1969