Experimental and kinetic modeling studies of the low-temperature oxidation of 2-methylfuran in a jet-stirred reactor

2-Methylfuran (MF), a promising biofuel, produced from non-edible biomass, is desirable as an alternative fuel or fuel additive to internal combustion engines. For a better understanding of the ignition process in engines, the low-temperature oxidation experiments of MF at the temperature range of 600 - 925 K and atmospheric pressure with different equivalence ratios (0.5, 1.0, and 2.0), were performed in a jet-stirred reactor. Synchrotron vacuum ultraviolet photoionization mass spectrometry was used to identify and measure the intermediates and products in the oxidation process, especially for the isomers (furfural/2ethylfuran and furan/vinyl ketene), species with identical mass-to-charge ratio (methanol/oxygen and aldehyde/carbon dioxide), and the other oxygenated and hydrocarbon products. The typical negative temperature-coefficient behavior was not observed in the low-temperature oxidation of MF. The dominant consumption pathways of MF in low-temperature oxidation are the hydroxyl radical/hydrogen atom addition reactions on the ring and hydrogen atom-abstraction reactions on the side methyl group by hydroxyl radical/hydroperoxyl radical/hydrogen atom, while the contribution of unimolecular decomposition reactions is almost negligible. 2-Furylmethyl radical is a key intermediate in the low-temperature oxidation of MF. Furfural and 2-ethylfuran, as the subsequent products from 2-furylmethyl low-temperature oxidation, were identified as the early-stage products. Besides, the important chemistry of other important species, especially acrolein and methyl vinyl ketone, were also discussed at different equivalence ratios. (c) 2021 The Combustion Institute. Published by Elsevier Inc. All rights reserved.

Automated summary

2-Methylfuran (MF) as a promising biofuel for internal combustion engines has been studied for its low-temperature oxidation pathways and key intermediate, with no typical negative temperature-coefficient behavior observed. The formation mechanisms of important products of MF low-temperature oxidation were investigated at different equivalence ratios.