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Published on: February 7, 2017
Enols are common intermediates in hydrocarbon oxidation.
Craig A Taatjes1, Nils Hansen, Andrew McIlroy
1Combustion Research Facility, Mail Stop 9055, Sandia National Laboratories, Livermore, CA 94551-0969, USA. cataatj@sandia.gov
Science (New York, N.Y.)
|May 14, 2005
Summary
Researchers discovered significant amounts of enol compounds in hydrocarbon flames, challenging current combustion models. These findings necessitate revisions to understand hydrocarbon oxidation mechanisms and fuel combustion processes.
Area of Science:
- Combustion Chemistry
- Chemical Kinetics
- Spectroscopy
Background:
- Hydrocarbon oxidation models are crucial for understanding combustion.
- These models typically include carbonyl (keto) compounds as intermediates.
- Less stable enol tautomers are generally excluded from standard models.
Purpose of the Study:
- To investigate the presence and role of enol compounds in hydrocarbon flames.
- To determine if enol flame chemistry can be explained by keto-enol tautomerization alone.
- To assess the impact of these findings on existing hydrocarbon oxidation mechanisms.
Main Methods:
- Photoionization mass spectrometry was used to identify molecular structures in flames.
- Flames from representative modern fuel blend compounds were analyzed.
- Concentration profiles of detected species were measured.
Main Results:
- Substantial quantities of two-, three-, and four-carbon enols were observed in flames.
- Observed enol concentrations and profiles could not be explained solely by keto-enol tautomerization.
- The presence of enols indicates a previously unaccounted-for chemical pathway.
Conclusions:
- Enol compounds are significant, previously overlooked intermediates in hydrocarbon flames.
- Current hydrocarbon oxidation models require revision to incorporate enol chemistry.
- Understanding enol formation and reactivity is essential for accurate combustion modeling.
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