1989 Volume 22 Issue 6 Pages 677-683
Monosilane pyrolysis was conducted over the temperature range of a fluidized-bed reactor (823 K–973 K) by use of both packed-bed and tubular free-space reactors, with and without seed silicon particles, respectively. In the packed-bed reactor, the heterogeneous reaction was predominant and most of the silicon produced was deposited on the seed silicon surface. In the free-space reactor, the homogeneous reaction was predominant and fine powder was formed. The conversion of monosilane obtained was analyzed, based on the assumption of first-order reaction to silane concentration. The homogeneous reaction rate and heterogeneous reaction rate were separated and the rate constants of both reactions were determined. The activation energies were 231 kJ and 193 kJ respectively. The rate obtained was compared with the previously reported kinetics, obtained under different conditions from the present experimental conditions. In a reaction zone with a number of particles, such as the emulsion phase of a fluidized bed, the contribution of the homogeneous reaction was found to be less than 10% for the particles and temperature range employed in the present study.
