Pyrolysis of 2-methylfuran/jet fuel surrogate blends: An experimental and kinetic modeling study

Owing to significant advantages over traditional biofuels, 2-methylfuran (MF) has arisen extensive interest as next generation biofuels. Atmospheric pressure pyrolysis of a 1:1 blend of MF with a three-component (3C) surrogate jet fuel was conducted in a flow tube using synchrotronphotoionization and molecular beam mass spectrometry techniques within a temperature range of 898-1223 K. Therein, the 3C surrogate fuel consists of 66.2% n-dodecane (NC12H26), 18.0% 1,3,5-trimethylcyclohexane (T135MCH) and 15.8% n-propylbenzene (NPB, A1C(3)H(7)). The detailed kinetic model including 579 species and 3474 reactions was developed via validating against both measured and literature data with reasonable agreement. MF exhibits no obvious influence on the 3C components pyrolysis. However, 3C mixtures play an important roles in MF decomposition: lower initial temperature and different decomposition pathways. In the meantime, n-propylbenzene (NPB) pyrolysis curve in 3C and 3C + MF significantly transfers to low temperature zone after 1000 K in contrast to pure NPB, while smaller change was found in the decomposition curve of n-dodecane. Compared with 3C pyrolysis, 3C + MF blends have less formation of aromatic species and light hydrocarbons except for vinylacetylene (C4H4) and acetylene (C2H2). Allyl radical (C3H3) has significant roles in benzene ring formation. The combination of allyl radical with propargyl radical producing benzene and H radical (alpha C3H5 + C3H3 = A1 + 2H) has the highest contribution to the benzene formation in both 3C and 3C + MF. Moreover, most of naphthalene (A2) formation is also related to C3H3 radical via reaction: A1CH(2) + C3H3 = A2 + H, rather than via HACA (hydrogen abstraction carbon addition) reaction. Interaction of fuel blends was mainly presented through the common and important sensitive reactions which are much to do with CH3 and H radicals. The overview of product distribution was investigated by providing comparisons of carbon conversion rates during the pyrolysis of 3C and 3C + MF. These results will be helpful to better understand the pyrolysis properties of MF/jet fuel surrogate blends and could contribute to developing new generation biofuels for aviation. (C) 2021 The Combustion Institute. Published by Elsevier Inc. All rights reserved.

Automated summary

The study found that 2-methylfuran (MF) has little effect on the pyrolysis of the three-component (3C) surrogate fuel, while the 3C mixtures play an important role in the decomposition of MF. Specific reactions produce substances like benzene rings and naphthalene, which have a significant impact on the formation of aromatic hydrocarbons and light hydrocarbons.