title: Isomer-specific fuel destruction pathways in rich flames of methyl acetate and ethyl formate and consequences for the combustion chemistry of esters.
abstract: The influences of fuel-specific destruction pathways on flame chemistry are determined for two isomeric ester fuels, methyl acetate, CH3(CO)OCH3, and ethyl formate, H(CO)OC2H5, used as model representatives for biodiesel compounds, and their potential for forming air pollutants is addressed. Measurements are presented of major and intermediate species mole fractions in premixed, laminar flat flames using molecular-beam sampling and isomer-selective VUV-photoionization mass spectrometry. The observed intermediate species concentrations 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 isomer favors the production of acetaldehyde. Ethyl formate also yields higher concentrations of the C2 species (C2H2 and C2H4) and C4 species (C4H2 and C4H4). Benzene concentrations, while larger for ethyl formate, are at least an order of magnitude smaller for both flames than seen for simple hydrocarbon fuels (ethylene, ethane, propene, and propane).
authors: Department of Chemistry, Bielefeld University, Universitätsstrasse 25, D-33615 Bielefeld, Germany.
authors: Patrick
authors: P
authors: Osswald
authors: Ulf
authors: U
authors: Struckmeier
authors: Tina
authors: T
authors: Kasper
authors: Katharina
authors: K
authors: Kohse-Höinghaus
authors: Juan
authors: J
authors: Wang
authors: Terrill A
authors: TA
authors: Cool
authors: Nils
authors: N
authors: Hansen
authors: Phillip R
authors: PR
authors: Westmoreland
mesh_terms: D000085:Acetates / Q000737:chemistry*; D004952:Esters / Q000737:chemistry*; D005390:Fires; D005563:Formic Acid Esters / Q000737:chemistry*; D007536:Isomerism; D008956:Models, Chemical
chemical_list: D000085:Acetates; D004952:Esters; D005563:Formic Acid Esters; C510888:ethyl formate; C046923:methyl acetate