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

Abstract

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 1200-1350 K, pressures from 2-2.5 atm and residence times of approximately 2 ms.Ignition delay times for mixtures of 0.75% 25DMF in argon have been measured at atmospheric pressure, temperatures of 1350-1800 K 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 80 bar, from 820-1210 K. This is supplemented with an oxidative speciation study of 25DMF in a jet-stirred reactor (JSR) from 770-1220 K, at 10.0 atm, residence times of 0.7 s 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 358 K, at atmospheric pressure from ϕ = 0.6-1.6. * address: Combustion Chemistry Centre, National University of Ireland, Galway, University Road Galway, Ireland. Phone: +353-91-494087. k.somers1@nuigalway.ie, URL: http://c3.nuigalway.ie/ (Kieran P. Somers).. Electronic Supplementary Information Electronic supplementary information includes:• Tabulations of all new experimental data • Pressure-time profiles for high pressure shock tube experiments and volume-time profiles used for corresponding simulations• A description of the optimized group additivity rules for substituted furans •The chemkin format kinetic mechanism, thermodynamic and transport files• A list of species structures and names for interpretation of kinetic mechanism and sensitivity analysis diagrams 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 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 HȮ 2 or CH 3 Ȯ 2 with the 5-methyl-2-furanylmethyl radical, forming a 5-methy...

Recent Trends in the Production, Combustion and Modeling of Furan-Based Fuels

“…As a result, a number of its kinetic models have been proposed [9,10,142,144]. The first 2,5-DMF kinetic model of 50 species and 181 elementary reactions was presented by Lifshitz et al [142].…”

“…The results showed good agreement between model predictions and experimental data, especially with respect to ignition delay times. An extensive chemical kinetic model was then developed by Somers et al [9]. The model contains 2768 reactions and 545 species, and it was developed to simulate 2,5-DMF ignition delay time and pyrolysis experiments performed in a single-pulse shock tube; laminar burning velocity data; and speciation measurements performed in a jet stirred reactor.…”

“…In a study by Eldeeb and Akih-Kumgeh [25], a combined model for 2,5-DMF and iso-octane combustion was developed, based on existing chemical kinetic models for the pure components [9,162]. This was the first effort with regards to the kinetic modeling of furan-gasoline blends.…”

Advanced Biofuels and Beyond: Chemistry Solutions for Propulsion and Production

“…Comparisonofexperimental ignition delay times for mixtures of 0.75 %2 ,5-DMF and 2.81 %, 5.625 %, and 11.25 %O 2 in Ar at 1bar (from Ref. [176]) versus predictionsw ith the mechanisms of Somers et al [176] (solid line), Sirjean et al [214] (dashed line), and TogbØ et al [178] (dotted line). Reproduced from Ref.…”

“…[163] This knowledge has led to the formulation of reaction classes and associated rate rules for alcohols,a ldehydes,a nd carbonylic species, which permit the further development of mechanisms for such compounds. [167,168] Quite recently,c hemical mechanisms have also been developed for fuels from second-generation processes and beyond, including larger alcohols, [164,165] ethers, [169] and ketones, [170,171] and as ubstantial amount of work has been devoted to the furans [172][173][174][175][176][177][178] and tetrahydrofurans,w hich are in the focus of the present Review. [69,179,180] It is interesting to understand how macroscopic properties such as derived cetane numbers (compare Section 2a nd Figure 1) for advanced biofuels relate to the chemical kinetics mechanisms,s ince such understanding can substantially support strategies for fuel design.…”