Effect of Fuel/Air Ratio Variations on Catalyst Performance and Hydrocarbon Emissions During Cold-Start and Warm-Up

962075

10/01/1996

Event
1996 SAE International Fall Fuels and Lubricants Meeting and Exhibition
Authors Abstract
Content
Effects of fuel/air equivalence ratio variations (Φ = 1.0±0.02) on engine-out and catalyst-out hydrocarbon (HC) mass and speciated emissions were measured under simulated cold-start conditions in order to suggest ways to optimize the engine-controls-catalyst system for minimum HC mass emissions and specific reactivity. A single-cylinder engine (installed in a temperature-controlled room and using commercial-grade gasoline) is run under controlled steady-state conditions (at 24 °C or -7 °C) which simulate cold starting. Speciated and total hydrocarbon emissions are measured from engine-out exhaust samples and from samples taken after an oven-temperature-controlled catalyst (either a fresh platinum/rhodium production catalyst, a 50,000 mile vehicle-aged catalyst, or a ceramic brick with standard washcoat containing no noble metal). Changes in engine fuel/air equivalence ratio (Φ = 1.0±0.02) have a small effect on engine-out HC mass emissions (± 10 %) and specific reactivity (0 - 2%). However, changing Φ from 1.02 (slightly rich) to 0.98 (slightly lean) has a large effect on catalyst performance - decreasing post-catalyst ozone forming potential values by a factor of 36 for a fresh catalyst and a factor of 6 for an aged catalyst.
Meta TagsDetails
DOI
https://doi.org/10.4271/962075
Pages
30
Citation
Drake, M., Sinkevitch, R., Quader, A., Olson, K. et al., "Effect of Fuel/Air Ratio Variations on Catalyst Performance and Hydrocarbon Emissions During Cold-Start and Warm-Up," SAE Technical Paper 962075, 1996, https://doi.org/10.4271/962075.
Additional Details
Publisher
Published
Oct 1, 1996
Product Code
962075
Content Type
Technical Paper
Language
English