The CO2 reforming of CH4 in a thermal diffusion column reactor (TDCR) was conducted from 800 degrees C to 1175 degrees C on a tungsten wire in a vertical and inclined (45 degrees) mode. Comparison was made with a horizontal pyrolysis quartz reactor with coiled wire. The wall temperature of the pyrolysis reactor was controlled by a tubular furnace. The longer coiled wire in this reactor gave higher conversion than the TDCR for comparable wire temperatures and flow rates. The conversion of CH4 and the yields of H-2, CO and H2O were compared with calculated values and indicate that the hot wire reactors are nonequilibrium systems due to the different diffusion characteristics of the reactants and products.