A chemical kinetic modeling study of indene pyrolysis

Abstract

An improved polycyclic aromatic hydrocarbon (PAH) model is developed to predict the decomposition of indene and the formation of large PAHs under pyrolytic conditions. This model is developed based on experimental study of pyrolytic kinetics of indene in a flow reactor at low and atmospheric pressures (30 and 760 Torr) by using synchrotron vacuum ultraviolet photoionization mass spectrometry (SVUV-PIMS). A general map of PAH growth is presented according to the observations in this study and those in literature. Indene dissociates via indanyl forming mono-cyclic aromatics and small intermediates, while its dominant decomposition product is indenyl. As a resonantly stabilized radical, indenyl serves as a platform molecule in PAH growth process which links small unsaturated hydrocarbons and mono-aromatic species to multi-cyclic ones. Reactions of indenyl radical are proposed to form commonly studied and recently observed PAHs. Rate constants of these reactions are evaluated by analyzing literature data of rate constant measurements, quantum chemical calculations and analogy to cyclopentadienyl radical. The main PAH formation pathways are the bimolecular addition reactions of indenyl radical with indene and a series of intermediates, forming C 10 -C 18 and larger PAHs. Meanwhile, radical chain reactions provide huge passage for PAH growth form

Determination of absolute photoionization cross‐sections of some aromatic hydrocarbons

“…Photoionization mass spectrometry (PIMS) has been used extensively for the analysis of organic molecules, 1,2 and for combustion studies in recent years 3–7 . In traditional electron ionization (EI) mass spectrometry of complex mixtures, typically carried out at an electron energy of 70 eV, a large number of peaks overlap including precursor ion and fragment ion signals.…”

Thermal Decomposition Kinetics of the Indenyl Radical: A Theoretical Study

“…Experimental and simulated profiles of various radicals like acetylene, cyclopentadienyl, and indenyl were presented in the work of Jin et al, 24 along with a kinetic model that treated indenyl decomposition using the rate coefficient expressions of Matsugi. 23 This model is considered as the base chemistry for further calculations in this work.…”

“…The rate parameters of Matsugi et al 23 have been incorporated into recent kinetic models of toluene oxidation and pyrolysis 22 and indene pyrolysis. 24 A recent experimental study of indenyl radical photolysis 25 has provided new insight into the dissociation chemistry of this important radical. Dissociation products were observed following irradiation at 193 and 248 nm, attributed to decomposition on the ground state following the absorption of two photons and subsequent internal conversion.…”

Continuous Butadiyne Addition to Propargyl: A Radical-Efficient Pathway for Polycyclic Aromatic Hydrocarbons

“…32 A recently published PAH model was employed as the base model for the simulations. 33 This model includes the HACA, HAVA, and RSR reactions of CHRCR, and PAC (e.g., phenyl addition to naphthalene and biphenyl) pathways. CBAC pathways were added to the base model along with the rate constants given in Table S3 (Supporting Information).…”

“…The simulations were performed using the burner-stabilized flame module of Cantera and a one-dimensional temperature profile . A recently published PAH model was employed as the base model for the simulations . This model includes the HACA, HAVA, and RSR reactions of CHRCR, and PAC (e.g., phenyl addition to naphthalene and biphenyl) pathways.…”