Experimental and kinetic modeling study of exo-TCD pyrolysis under low pressure

Abstract

The exo-TCD (exo-tricyclo[5.2.1.02,6]decane) pyrolysis (3.0vol.% exo-TCD in argon) was performed in a flow tube reactor at a temperature range of 900–1600K under low pressure (667Pa). The identification of products or intermediates and the isomeric distinction were accomplished by synchrotron vacuum ultraviolet photoionization mass spectrometry (SVUV-PIMS). Approximately 28 species were identified and quantified by near-threshold measurements of photoionization mass spectrum and photoionization efficiency spectrum. Meanwhile, the initial unimolecular decomposition rate of exo-TCD was estimated using transition states theory and Rice–Ramsperger–Kassel–Marcus (RRKM) theory. A detailed kinetic model of exo-TCD pyrolysis was developed including 316 species and 807 reactions. The simulation results generally agree well with the experimental data. ROP and sensitivity analysis indicate that under lower pressure the initial decomposition of exo-TCD is dominant by diradical channel rather than the unimolecular decomposition or H-abstraction channels, and that the methyl-cyclicC5 and methylene-cyclicC5 species may be one of the principal precursors for the formation of aromatics (benzene, toluene, etc.).