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Interaction Between Gasoline Properties and Engine Management System and Effects on 3-Way Catalyst Efficiency
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Abstract
The EPEFE study (European Programme on Emissions, Fuels and Engine Technologies), /1/ and other programmes have identified an increase in tailpipe NOx emissions with reduced gasoline aromatics content for modern 3-way controlled catalyst vehicles. This effect occurs with fully warmed-up catalyst under closed-loop operation. In order to understand the reasons for this effect VW and Shell have mechanistically investigated the effects of fuel properties on EMS (engine management system) and catalyst performance. Fuels with independent variation of oxygen, aromatics and mid-range volatility were tested in different VW engines. λ was monitored using sensors located both pre and post catalyst.
The results confirmed that reducing gasoline aromatics content reduced engine-out emissions but increased tailpipe NOx emissions. It could be shown that differences in H/C ratio led to differences in the hydrogen content of engine-out emissions which affected the reading of the λ sensor. Reducing aromatics resulted in a lean shift in λ with the consequence of a reduced NOx conversion particularly at operating conditions which were already calibrated slightly lean. Activating the feedback control by the second sensor as used for OBD II could effectively compensate for the λ shift effect and resulted in a considerably reduced fuel sensitivity. Therefore with activated feedback control all regulated emissions were reduced over the composite European driving cycle with reduced fuel aromatics content due to lower pre light-off emissions.
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Citation
Graupner, J., Lange, W., Kostka, J., and König, A., "Interaction Between Gasoline Properties and Engine Management System and Effects on 3-Way Catalyst Efficiency," SAE Technical Paper 972839, 1997, https://doi.org/10.4271/972839.Also In
References
- “European Programme on Emissions, Fuels and Engine Technologies” ACEA and EUROPIA report November 1995
- Morgan T.D.B. et al. “An integrated study of the effects of gasoline composition on exhaust emissions, part 1: Programme outline and results on regulated emissions” SAE 932678 Philadelphia 1993
- LeJeune A. McDonald C.R. Morgan T.D.B. Graupner O. “The independent effects of fuel aromatics content and mid-range volatility on tailpipe emissions from current technology European vehicle fleets” SAE 962026 San Antonio 1996
- Wedekind B. et. al. “The independent effect of mid-range, back-end volatility and aromatics on emissions from two European gasoline engines” SAE 952522 Toronto 1995
- McDonald C.R. Morgan T.D.B. Graupner O. Wilkinson E. “The independent effects of fuel aromatics content and mid-range volatility on tailpipe emissions from current technology European vehicle fleets” SAE 962026 San Antonio 1996
- van den Brink P.J. McDonald C.M. “Influence of the fuel hydrocarbon composition on nitric oxide conversion in 3-way catalysts: the NOx/Aromatics effect” Applied catalysis B: environmental 6 L97 L103 1995
- van den Brink P.J. McDonald C.M. “The influence of the fuel hydrocarbon composition on NO conversion in 3-way catalysts: the NOx/Aromatics effect” SAE 952399 Toronto 1995
- Lee G.R. et al. “The role of methane on catalyst conversion of NOx: a study based on FTIR” SAE 961155 Dearborn 1996
- McArragher S. van den Brink P.J. McDonald C.M. Graupner O. “NOx emissions from catalyst cars: the effect of gasoline aromatic content” 5th CEC international symposium on the performance evaluation of automotive fuels and lubricants Gothenburg 1997
- Robert Bosch GmbH Stuttgart 1993
- Eltinge L. “Fuel-Air Ratio and Distribution from Exhaust Gas Composition” SAE 680114 1968
- Benson J.D. Steinbrink R. “Gasoline Quality required for future low emission vehicles” 5th CEC international symposium on the performance evaluation of automotive fuels and lubricants Gothenburg 1997
- Kostka J. et. al. 1996
- Kostka J. TU Berlin