Isomer-Specific Fuel Destruction Pathways in Rich Flames of Methyl Acetate and Ethyl Formate and Consequences for the Combustion Chemistry of Esters

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• 作者：Patrick Osswald ; Ulf Struckmeier ; Tina Kasper ; Katharina Kohse-Hö ; inghaus ; Juan Wang ; Terrill A. Cool ; Nils Hansen ; Phillip R. Westmoreland
• 刊名：Journal of Physical Chemistry A
• 出版年：2007
• 出版时间：May 17, 2007
• 年：2007
• 卷：111
• 期：19
• 页码：4093 - 4101
• 全文大小：223K
• 年卷期：v.111,no.19(May 17, 2007)
• ISSN：1520-5215

文摘

The influences of fuel-specific destruction pathways on flame chemistry are determined for two isomericester fuels, methyl acetate, CH₃(CO)OCH₃, and ethyl formate, H(CO)OC₂H₅, used as model representativesfor biodiesel compounds, and their potential for forming air pollutants is addressed. Measurements are presentedof major and intermediate species mole fractions in premixed, laminar flat flames using molecular-beamsampling and isomer-selective VUV-photoionization mass spectrometry. The observed intermediate speciesconcentrations depend crucially on decomposition of the different radicals formed initially from the fuels.The methyl acetate structure leads to preferential formation of formaldehyde, while the ethyl formate isomerfavors the production of acetaldehyde. Ethyl formate also yields higher concentrations of the C₂ species (C₂H₂and C₂H₄) and C₄ species (C₄H₂ and C₄H₄). Benzene concentrations, while larger for ethyl formate, are atleast an order of magnitude smaller for both flames than seen for simple hydrocarbon fuels (ethylene, ethane,propene, and propane).