CHEMISTRY AND KINETICS OF CHEMICAL-VAPOR-DEPOSITION OF PYROCARBON - II - PYROCARBON DEPOSITION FROM ETHYLENE, ACETYLENE AND 1,3-BUTADIENE IN THE LOW-TEMPERATURE REGIME

Pyrocarbon deposition from ethylene, acetylene and 1,3-butadiene was s tudied with a vertical hot-wall reactor at ambient pressure and 1000 d egrees C; initial partial pressures of the hydrocarbons and residence time were varied. Steady-state pyrocarbon deposition rates and corresp onding compositions of the gas-phase were determined. Reaction models describing homogeneous gas-phase and heterogeneous pyrocarbon depositi on reactions were derived and applied for simulation of pyrocarbon dep osition rates and the inhibiting effect of hydrogen. This latter effec t is ascribed to a blocking of active sites at the growing pyrocarbon surface. (C) 1998 Elsevier Science Ltd. All rights reserved.