A comprehensive experimental and detailed chemical kinetic modelling study of 2,5-dimethylfuran pyrolysis and oxidation

• Published in: Combustion and flame 2013-11, Vol.160 (11), p.2291-2318
• Main Authors: Somers, Kieran P., Simmie, John M., Gillespie, Fiona, Conroy, Christine, Black, Gráinne, Metcalfe, Wayne K., Battin-Leclerc, Frédérique, Dirrenberger, Patricia, Herbinet, Olivier, Glaude, Pierre-Alexandre, Dagaut, Philippe, Togbé, Casimir, Yasunaga, Kenji, Fernandes, Ravi X., Lee, Changyoul, Tripathi, Rupali, Curran, Henry J.
• Format: Article
• Language: English
• Subjects: 2,5-Dimethylfuran; Alternative fuels. Production and utilization; Applied sciences; Biofuel; Chemical Sciences; Combustion. Flame; Detailed chemical kinetic modelling; Energy; Energy. Thermal use of fuels; Exact sciences and technology; Fuels; Jet-stirred reactor; Laminar burning velocity; Miscellaneous; or physical chemistry; Shock tube; Theoretical and; Theoretical studies. Data and constants. Metering
• ISSN: 0010-2180; 1556-2921
• DOI: 10.1016/j.combustflame.2013.06.007

The pyrolytic and oxidative behaviour of the biofuel 2,5-dimethylfuran (25DMF) has been studied in a range of experimental facilities in order to investigate the relatively unexplored combustion chemistry of the title species and to provide combustor relevant experimental data. The pyrolysis of 25DMF has been re-investigated in a shock tube using the single-pulse method for mixtures of 3% 25DMF in argon, at temperatures from 1200 to 1350K, pressures from 2 to 2.5atm and residence times of approximately 2ms. Ignition delay times for mixtures of 0.75% 25DMF in argon have been measured at atmospheric pressure, temperatures of 1350–1800K at equivalence ratios (ϕ) of 0.5, 1.0 and 2.0 along with auto-ignition measurements for stoichiometric fuel in air mixtures of 25DMF at 20 and 80bar, from 820 to 1210K. This is supplemented with an oxidative speciation study of 25DMF in a jet-stirred reactor (JSR) from 770 to 1220K, at 10.0atm, residence times of 0.7s and at ϕ=0.5, 1.0 and 2.0. Laminar burning velocities for 25DMF-air mixtures have been measured using the heat-flux method at unburnt gas temperatures of 298 and 358K, at atmospheric pressure from ϕ=0.6–1.6. These laminar burning velocity measurements highlight inconsistencies in the current literature data and provide a validation target for kinetic mechanisms. A detailed chemical kinetic mechanism containing 2768 reactions and 545 species has been simultaneously developed to describe the combustion of 25DMF under the experimental conditions described above. Numerical modelling results based on the mechanism can accurately reproduce the majority of the experimental data. At high temperatures, a hydrogen atom transfer reaction is found to be the dominant unimolecular decomposition pathway of 25DMF. The reactions of hydrogen atom with the fuel are also found to be important in predicting pyrolysis and ignition delay time experiments. Numerous proposals are made on the mechanism and kinetics of the previously unexplored intermediate temperature combustion pathways of 25DMF. Hydroxyl radical addition to the furan ring is highlighted as an important fuel consuming reaction, leading to the formation of methyl vinyl ketone and acetyl radical. The chemically activated recombination of HȮ2 or CH3Ȯ2 with the 5-methyl-2-furanylmethyl radical, forming a 5-methyl-2-furylmethanoxy radical and ȮH or CH3Ȯ radical is also found to exhibit significant control over ignition delay times, as well as being important reactions in