Experimental and Kinetic Modeling Study of 2‑Methylfuran Pyrolysis at Low and Atmospheric Pressures

The
pyrolysis of 2-methylfuran (MF) was studied from 900 to 1530
K in a flow reactor at 30 and 760 Torr. Synchrotron vacuum ultraviolet
photoionization mass spectrometry and gas chromatography were used
for identification and mole fraction measurements of pyrolysis products,
especially free radicals and aromatics. Specific products were observed
for the two main unimolecular decomposition pathways of MF, such as
propargyl radical, methyl radical, 1-butyne, and carbon monoxide.
A previous kinetic model of MF was updated on the basis of recent
theoretical and modeling progresses, especially for the aromatic formation
sub-mechanism. The updated model was validated by the new pyrolysis
data. Kinetic analyses including rate of production analysis, and
sensitivity analysis were used to provide insight into the pyrolysis
chemistry of MF, especially the decomposition of MF and aromatic formation.
The pyrolysis of MF was found with the kinetic characteristics of
both furan pyrolysis and 2,5-dimethylfuran (DMF) pyrolysis. The decomposition
of MF in pyrolysis is initiated by the unimolecular dissociation pathway,
producing propargyl and acetyl radicals. Aromatics were observed with
higher concentration levels in MF pyrolysis than those in DMF pyrolysis.
The high concentration levels of precursors of aromatics, especially
propargyl radical, are responsible for the enhanced aromatic formation
in MF pyrolysis.