Cédric Descamps

Correlation Between Homogeneous Propane Pyrolysis and Pyrocarbon Deposition

Pyrocarbon deposition through propane pyrolysis is studied in a 1-D hot-wall CVD furnace. The gas-phase pyrolysis is modeled with a partially reduced kinetic mechanism leading to polycyclic aromatic compounds (PAHs). The C2-C4 and C3 reaction paths are in competition for benzene formation. There is also an independent C3-C5 path leading to naphthalene. The gas-phase concentrations are correlated with experimental data including in situ Fourier transform infrared spectra intensities, pyrocarbon deposition rates, and pyrocarbon nanotextures. Rough laminar pyrocarbon deposition appears to be more related to PAHs than smooth laminar pyrocarbon.

Extension of the bifurcation method for diffusion coefficients to porous medium transport

We present an extension of Bartletts bifurcation method for the approximate computation of multicomponent diffusion coefficients in a gaseous mixture to diffusion in porous media. On behalf of the remark that the bifurcation coefficients Fi are merely proportional to the square root of the molar masses Mi, we state that Knudsen diffusion may also be represented through some bifurcation factor FK. This approximation is tested in a variety of cases, displaying good results except for very light gas species.