FUEL 12 |
| The low temperature ignition behavior of methyl decanoate, a biodiesel relevant compound, was investigated in a motored engine experiment. Premixed charges of fuel and air were delivered to the engine, and the extent of autoignition was controlled by varying the compression ratio. Methyl deaconate exhibited two-stage ignition, with low temperature heat release (LTHR), or cool flame, followed by the main combustion event. FTIR analysis of the exhaust gas revealed that the ester group undergoes decarboxylation, or formation of carbon dioxide through unimolecular decomposition, not oxidation. When decarboxylation occurs in oxygenated diesel fuels, it reduces their effectiveness at reducing PM emissions because the oxygen is not fully utilized. The condensable species produced during LTHR were further analyzed via GC/MS, and a large number of species containing both methyl ester groups and additional carbonyl functionalities were identified. It was concluded the initial LTHR reactions involve only the aliphatic chain and are similar to those of n-heptane. Decarboxylation does not occur until the aliphatic chain has been largely consumed by LTHR reactions. |
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Biofuels for Transportation
8:55 AM-12:05 PM, Sunday, 26 March 2006 Georgia World Congress Center -- C204, Oral
Division of Fuel Chemistry |