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.

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Waste to energy is a key driver to achieve a clean and virtuous renewable cycle. Among others, the processes to convert organic matter in wastes from automotive residues, mainly composed of rubbers and foams [ethylene propylene diene monomer (EPDM) and polyurethane (PUR)], polyolefin plastics [polypropylene (PP) and polyethylene (PE)], styrenic plastics [acrylonitrile butadiene styrene (ABS) and polystyrene (PS)], and other thermoplastics [polyvinyl chloride (PVC) and polycarbonate (PC)], into a liquid fuel are now reliable. This new, atypical, and uncharted fuel is expected to emit large levels of pollutants, bringing new challenges that must be resolved by the combustion community. Advanced combustion modes appear to be a solution to enhance the efficiency and cutoff the NO x and soot particle emissions. The present paper addresses the scarcity of experimental data by investigating the autoignition in a rapid compression machine. The pressure and temperature were swept from 10 to 20 bar and from 700 to 880 K, respectively, and the equivalence ratio was equal to 0.5. These conditions match with the homogeneous charge compression ignition (HCCI) mode operating with exhaust gas recirculation, especially for the low to intermediate (intermediate to high) temperature (pressure). The studied fuel is the light fraction of the synthetic crude oil, described by high-alkene and high-oxygenate levels. Several specificities have been detected: a limited lowtemperature reactivity and a low negative temperature coefficient. Combustion simulation will be carried out in further work to determine to what extent advanced combustion modes will play a role to achieve a clean combustion in a waste-to-energy perspective.

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The viability of the use of ortho-cresol as a bio-blendstock or antiknock additive from lignocellulosic biomass is assessed; Ignition delays of ortho-cresol within blends with iso-octane are measured with the ULille rapid compression machine, and compared with results from the literature; It is shown that ortho-cresol has a strong inhibiting effect on the reactivity towards ignition, most notably in the Negative Temperature Coefficient region; This effect is found to originate from competition with iso-octane on the OH radicals, where the reactivity of ortho-cresol with these radicals does not lead to radical chain-branching.

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