2,5-Dimethyltetrahydrofuran combustion: Ignition delay times at high and low temperatures, speciation measurements and detailed kinetic modeling

Abstract

Ignition delays of stoichiometric mixture of 2,5-dimethyltetrahydrofuran/O 2 /inert mixtures were measured at temperatures ranging from 650 to 1300 K in a RCM and in a shock tube. Operating pressures ranged from 10 to 40 bar at higher temperature (ST) and 10 to 20 bar at lower temperatures (RCM). The ignition delay times exhibit a slight deviation from Arrhenius behaviour, and limited low-temperature reactivity. This behaviour is similar to other cyclic ethers studied in comparable conditions namely THF, 2-MTHF and 3-MTHF, where 2,5-dimethylterahydrofuran (2,5-DMTHF) is showing the lowest reactivity of this series of cyclic ethers.Detailed speciation and quantification of the intermediates formed by a stoichiometric 2,5-DMTHF/O 2 /N 2 mixture in the combustion chamber of the RCM was performed at different times between top dead center and the ignition event for T c = 712 K and p TDC = 10 bar. The major fuel specific species observed are 2,5-dimethylfuran, 2,6-dimethyl-1,3-diox-4-ene, hexa-2,5-dione, 1-(2methylcyclopropyl)ethanone, and hex-3-en-2-one.To provide further insight into the kinetics of the oxidation of 2,5-DMTHF, a comprehensive kinetic model was developed and validated upon the acquired experimental data. Reaction pathway analysis and sensitivity analysis give an overview of the oxidation process of 2,5-DMTHF and elucidates the formation of the experimentally observed fuel-specific intermediates.

Experimental and modeling study of the high-temperature combustion chemistry of tetrahydrofurfuryl alcohol

“…It can be easily produced via hydrogenation of furfural which is accessible from lignocellulosic biomass [1,2]. This biofuel family has been extensively investigated in terms of productions, engine performance, and combustion chemistry [3][4][5][6]. For THFA, studies on production methods [1,2], atomization/spray propagation [7], ignition characteristics [8] are known, and it has been suggested as a biofuel candidate for SI engines [8].…”

Is ortho-Cresol a Viable Lignocellulosic Blendstock? A Kinetic Study of Its Co-Oxidation within a Surrogate Fuel

“…The ULille RCM was used to measure the ignition delays of stoichiometric isooctane/ortho-cresol blends at several blending ratios between 0 and 40% mol. ortho-cresol in the fuel blend, and at pressures between 14 and 20 bar, and temperatures between 688 and 850 K. Because this experimental setup has been described extensively in the literature before [11][12][13], a schematic being given in [14], only the features relevant to this work will be described here. Mixtures of iso-octane, ortho-cresol, dioxygen, and inert gases were prepared using the partial pressure method inside a heated mixture preparation facility, whose temperature was fixed as superior to the one necessary for a vapor pressure of all compounds superior to twice the required one.…”

A kinetic investigation on the synergistic low-temperature reactivity, antagonistic RON blending of high-octane fuels: Diisobutylene and cyclopentane

“…IDTs of binary and ternary blends featuring iC8, CPT, and DIB were measured with the ULille rapid compression machine (RCM), which has already been used on numerous studies of the low-tointermediate temperature combustion kinetics of hydrocarbons. Only a brief explanation of the experimental apparatus is given here, hence the readers are encouraged to look for more details from the historical bibliography [31,32].…”

“…IDT is defined as the elapsed time between the end of the compression and the moment where the pressure rise rate is at its maximum value, as depicted in Fig To gain insight on the low-temperature combustion kinetics of these blended fuels, the reacting mixture inside the combustion chamber was sampled during the ignition delay period and analyzed with a gas chromatography/mass spectrometry (GC/MS) bench to quantify and identify the stable intermediate species which are formed during the ignition delay period. Such an experimental approach is also useful to develop kinetic models and/or assess the model validity, as demonstrated for example in a recent 2,5dimethyltetrahydrofuran study [31]. Sampling is realized through expansion of the compressed gas into a dedicated sampling canister, with a volume ratio between the combustion chamber and the canister of without stopping the engine as required in the ASTM standard procedure [36].…”