High resolution gas chromatographic determination of the atmospheric reactivity of engine-out hydrocarbon emissions from a spark-ignited engine
✍ Scribed by Kaiser, Edward W. ;Siegl, Walter O.
- Publisher
- John Wiley and Sons
- Year
- 1994
- Tongue
- English
- Weight
- 858 KB
- Volume
- 17
- Category
- Article
- ISSN
- 0935-6304
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✦ Synopsis
Abstract
The reactivities of engine‐out exhaust hydrocarbon (HC) emissions in photochemical smog formation have been determined for three fuels (isooctane, an aromatic blend, and a gasoline) in a single‐cylinder, spark‐ignited engine. High resolution capillary GC was used to determine the mole fractions of the exhaust hydrocarbon species. Temperature programmed chromatography on a single capillary column was sufficient to separate the major exhaust species. A library of approximately 160 hydrocarbon species was used to identify typically 90–95 % of the HC species present. GC‐MS was used selectively to verify peak assignments.
The effect of engine operating parameters (fuel‐to‐air ratio, spark timing, and speed) on reactivity was examined. Engine operating parameters affect both total emissions [g/mile] and the specific atmospheric reactivity [g ozone/g HC emissions] of these emissions. Changing the operating parameters to control total emissions may not be as effective as expected in controlling the total reactivity [g ozone/mile] of the emissions because the specific reactivity can also change simultaneously. Effects of changes in operating parameters differ significantly as the type of fuel is varied. The ability to measure exhaust hydrocarbon species emissions accurately and quickly will increase in importance as reactivity‐based emissions standards come into widespread use.