A one-dimensional, nonisothermal model is developed to describe the thermal dissociation of methane to hydrogen and carbon black occurring in a fluid-wall aerosol flow reactor. The model expressions are scaled and nondimensionalized to determine the minimum parametric representation of the system. The sensitivity of this thermal dissociation to three parameters (flow rate of carbon particles fed to initiate the reaction, carbon particle radius, and reactor wall temperature) is studied. The results of the study indicate that in order to achieve nearly complete conversion, high reactor wall temperatures must be maintained. In addition, micron-sized carbon black particles must be fed into the reactor to enhance the heat transfer to the gas phase. The actual flow rate of particles fed is not critical, as long as some flow rate of fine particles is maintained. (C) 2003 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.