Detailed chemical kinetic oxidation mechanism for a biodiesel surrogate

Abstract

A detailed chemical kinetic mechanism has been developed and used to study the oxidation of methyl decanoate, a surrogate for biodiesel fuels. This model has been built by following the rules established by Curran et al. for the oxidation of n-heptane and it includes all the reactions known to be pertinent to both low and high temperatures.Computed results have been compared with methyl decanoate experiments in an engine and oxidation of rapeseed oil methyl esters in a jet stirred reactor. An important feature of this mechanism is its ability to reproduce the early formation of carbon dioxide that is unique to biofuels and due to the presence of the ester group in the reactant. The model also predicts ignition delay times and OH profiles very close to observed values in shock tube experiments fueled by n-decane. These model capabilities indicate that large nalkanes can be good surrogates for large methyl esters and biodiesel fuels to predict overall reactivity, but some kinetic details, including early CO 2 production from biodiesel fuels, can be predicted only by a detailed kinetic mechanism for a true methyl ester fuel.The present methyl decanoate mechanism provides a realistic kinetic tool for simulation of biodiesel fuels.3

Detailed chemical kinetic reaction mechanisms for primary reference fuels for diesel cetane number and spark-ignition octane number

“…Further kinetic analysis is needed to extend this conclusion to other classes of hydrocarbon fuels such as those with aromatic rings and double bonds, but recent studies of alkyl ester fuels such as those in biodiesel fuels [11] show very similar ignition behavior as that observed for the n-alkanes shown in Fig. 3.…”

“…Development of detailed chemical kinetic reaction mechanisms using the same reaction pathway and rate classes have provided kinetic tools for ignition and combustion studies of many other fuels [4][5][6][7][8][9][10][11][12] to study the role of fuel molecular structure on hydrocarbon ignition, and they provided a starting point to development of more general surrogate fuels for gasoline in SI engines [13] and diesel fuel in diesel engines [14].…”

Experimental and kinetic modeling study of extinction and ignition of methyl decanoate in laminar non-premixed flows

“…Previous studies of ignition and combustion of methyl decanoate have been focused on premixed systems [5][6][7]. The present study considers combustion of methyl decanoate in nonpremixed, aerodynamically strained flows.…”

“…These same methyl esters are found in biodiesel derived from other vegetable oils such as rapeseed oil, but the proportions differ. Methyl esters in particular methyl butanoate (n-C 3 H 7 C(=O)OCH 3 ) and methyl decanoate (n-C 9 H 19 C(=O)OCH 3 ) have been proposed as possible surrogates for biodiesel [1][2][3][4][5][6][7]. The present study is focused on combustion of methyl decanoate.…”

“…al. [7] developed a reliable kinetic model for describing the combustion of methyl decanoate, with a chain of 10 carbon atoms with a methyl ester group attached. Methyl decanoate reacts in a manner that is much closer to actual biodiesel fuel than methyl butanoate, including both early production of CO 2 from the methyl ester group and burning in a manner very similar to biodiesel derived from rapeseed based methyl esters.…”