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Effects of Cetane Number, Aromatics, and Oxygenates on Emissions From a 1994 Heavy-Duty Diesel Engine With Exhaust Catalyst
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Abstract
A Coordinating Research Council sponsored test program was conducted to determine the effects of diesel fuel properties on emissions from two heavy-duty diesel engines designed to meet EPA emission requirements for 1994. Results for a prototype 1994 DDC Series 60 were reported in SAE Paper 941020. This paper reports the results from a prototype 1994 Navistar DTA-466 engine equipped with an exhaust catalyst.
A set of ten fuels having specific variations in cetane number, aromatics, and oxygen were used to study effects of these fuel properties on emissions. Using glycol diether compounds as an oxygenated additive, selected diesel fuels were treated to obtain 2 and 4 mass percent oxygen. Cetane number was increased for selected fuels using a cetane improver.
Emissions were measured during transient FTP operation of the Navistar engine tuned for a nominal 5 g/hp-hr NOx, then repeated using a 4 g/hp-hr NOx calibration. To determine models for estimating fuel effects on emissions, multiple linear regression analysis of the emissions data was conducted. For this catalyst-equipped engine, the models indicated that increasing cetane number reduced HC, CO, and NOx emissions. Increased cetane number reduced PM emissions for the 4 g/hp-hr NOx calibration, but had no statistically significant effect on PM for the 5 g/hp-hr NOx calibration. For both NOx calibrations, increasing aromatic content increased PM emissions, and increasing oxygen reduced PM emissions.
THE EFFECTS OF oxygenated diesel fuels and other selected fuel properties on engine emissions have been investigated on engines that meet 1991 and 1994 EPA emissions regulations. (1, 2, 3, 4, 5, 6 and 7)* By incorporating engine design changes that control both HC emissions and the soluble organic fraction (SOF) of total particulate emissions, most heavy-duty diesel engines meet the 1994 regulations without using an exhaust aftertreatment device, such as a catalytic converter. For those diesel engines that require the use of a catalytic converter to meet emissions regulations, the relationship between fuel properties and exhaust emissions may be different than engines without a converter. The Coordinating Research Council-Air Pollution Research Advisory Committee (CRC-APRAC) developed the VE-10 Project to investigate the effects of cetane number, aromatic content, and oxygen level on regulated and selected unregulated emissions from a Navistar DTA-466 engine equipped with a catalytic converter. This engine was calibrated for 1994 emission regulations limiting NOx emissions to 5 g/hp-hr and PM to 0.1 g/hp-hr. This engine was adjusted to approach 4 g/hp-hr NOx by retarding fuel injection timing to further investigate fuel effects on emissions for combustion processes limited to lower NOx.
Under the VE-10 program, similar test work was performed using a Detroit Diesel Corporation (DDC) Series 60 engine without a catalyst. Test work on the DDC engine was published in SAE Paper 941020. Conclusions about that engine indicated that increasing cetane number decreased CO and NOx emissions, but had no significant effect on PM emissions. Increasing aromatics increased NOx emissions for the Series 60. Adding oxygen to diesel fuel decreased CO and PM levels, but slightly increased NOx emissions.
For purposes of this paper, discussions of emission results and the associated statistical analysis are limited to the Navistar engine.
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Spreen, K., Ullman, T., and Mason, R., "Effects of Cetane Number, Aromatics, and Oxygenates on Emissions From a 1994 Heavy-Duty Diesel Engine With Exhaust Catalyst," SAE Technical Paper 950250, 1995, https://doi.org/10.4271/950250.Also In
References
- Rosenthal, M.L. Bendinsky, T. “The Effects of Fuel Properties and Chemistry on the Emissions and Heat Release of Low-Emission Heavy-Duty Diesel Engines,” SAE Paper 932800 October 18-21 1993
- Liotta, F.J. Montalvo, D.A. “The Effect of Oxygenated Fuels on Emissions from a Modern Heavy-Duty Diesel Engine,” SAE Paper 932734 October 18-21 1993
- Nikanjam, M. “Development of the First CARB Certified California Alternative Diesel Fuel,” SAE Paper 930728 March 1-5 1993
- McCarthy, C.I. Slodowski, W.J. Sienicki, E.J. Jass, R.E. “Diesel Fuel Property Effects on Exhaust Emissions from a Heavy-Duty Diesel Engine that Meets 1994 Emissions Requirements,” SAE Paper 922267 October 19-22 1992
- Bennethum, J.E. Winsor, R.E. “Toward Improved Diesel Fuel,” SAE Paper 912325 October 7-10 1991
- Ullman, T.L. Mason, R.L. Montalvo, D.A. “Study of Fuel Cetane Number and Aromatic Content Effects on Regulated Emissions form a Heavy-Duty Diesel Engine,” Final Report prepared for the Coordinating Research Council September 1990
- Ullman, T.L. “investigation of the Effects of Fuel Composition and Injection and Combustion System Type on Heavy-Duty Diesel Exhaust Emissions,” Final Report prepared for the Coordinating Research Council March 1989
- Bernhard J. Kraus Dr.
- PM humidity correction coefficients derived from EMA/EPA round-robin emission program on a DDC Series 60 engine and other engines tested at EMA member laboratories
- Ullman, T.L. Spreen, K.B. Mason, R.L. “Effects of Cetane Number, Cetane Improver, Aromatics, and Oxygenates on 1994 Heavy-Duty Diesel Engine Emissions,” SAE Paper 941020 February 28 March 3 1994
- Ullman, T.L. Spreen, K.B. Mason, R.L. “Effects of Cetane Number on Emissions from a Prototype 1998 Heavy-Duty Diesel Engine,” SAE Paper 950251 February 27 March 3 1995