Oxidation of methyl and ethyl butanoates

Abstract

This paper describes an experimental and modeling study of the oxidation of methyl and ethyl butanoates in a shock tube. The ignition delays of these two esters mixed with oxygen and argon for equivalence ratios from 0.25 to 2 and ester concentrations of 0.5% and 1% were measured behind a reflected shock wave for temperatures from 1250 to 2000 K and pressures around 8 atm. To extend the range of studied temperatures in the case of methyl butanoate, two sets of measurements were also made in a jet-stirred reactor at 800 and 850 K, at atmospheric pressure, at residence times varying between 1.5 and 9 s and for equivalence ratios of 0.5 and 1. Detailed mechanisms for the combustion of methyl and ethyl butanoates have been automatically generated using a version of EXGAS software improved to take into account these oxygenated reactants. These mechanisms have been validated through comparison of simulated and experimental results in both types of reactor. The main reaction pathways have been derived from reaction flux and sensitivity analyses performed at different temperatures.

Oxidation of small unsaturated methyl and ethyl esters

“…The presence of oxygen atoms in the involved radicals can have a significant impact on the values of the activation energies of the decomposition by β-scission. We have then used here the value calculated for saturated esters using quantum calculations [23].…”

“…The detailed chemical kinetic reaction mechanisms presented here have been developed using the version of EXGAS software recently improved to take into account methyl and ethyl esters [23].…”

“…1 showing that in all of them, the double C C bond is conjugated with the carbonyl group. Combined with our previous work on the ignition of methyl and ethyl butanoates under similar conditions [23], trends about the influence of the structure of the ester on its ignition properties have been derived. Note that the four esters studied here are primary products of the oxidation of methyl or ethyl butanoate.…”

Detailed chemical kinetic reaction mechanism for biodiesel components methyl stearate and methyl oleate

“…While numerous kinetic modeling studies of smaller methyl esters have been carried out [6][7][8][9][10][11][12][13], few studies of large methyl ester fuels have appeared. Dagaut et al [14] studied the oxidation of rapeseed methyl ester fuel in a jet-stirred reactor lean at 10 atm pressure.…”

“…Based on their previous works on alkanes [19] and the success of the methyl decanoate mechanism [16], the Nancy combustion group updated the reaction pathway and rate rules used by the software EXGAS, for the automatic generation of detailed kinetic models, for methyl and ethyl esters, leading to their application to mechanisms for methyl and ethyl butanoates [13] and larger methyl esters up to methyl decanoate [20] and methyl palmitate [21].…”