Kinetic model of gas-phase reactions in the chemical vapor deposition of propane

The chemical kinetics of propane pyrolysis in chemical vapor deposition (CVD) is investigated in 1074 reactions consisting of 285 species to understand chemistry of CVD from propane. The reaction mechanism is modeled in a perfectly stirred reactor and a continuous tubular reactor, to produce a 0-D and a 1-D propane pyrolysis model, respectively. The concentration profiles of gas-phase products in the axial direction of the reactor as functions of temperature and residence time are computed with the DETCHEM software package designed for computing time-dependent homogeneous reactions. Comparison between simulated and experimental results shows that the mechanism gives the formation pathway for all major products and can predict the concentration profiles of minor products. Main reaction paths and crucial reaction steps have been determined at 1248 K for 1s by analyzing the flux of the main products. The significant roles of radicals such as propargyl, cyclopentadienyl and indenyl in the formation of polyaromatic hydrocarbons were discussed.