Partial oxidation of methane - Effect of reaction parameters and catalyst composition on the thermal profile and heat distribution

The partial oxidation of methane was carried out using new catalysts obtain ed by calcination and reduction of Mg/Al hydrotalcite-type precursors, cont aining Rh, Ni or Rh/Ni. The preparation methodology ensured high dispersion of the metal and activity in the partial oxidation of methane. To study th e activity, the reaction in autothermal conditions was investigated using I R thermography to monitor the surface temperature. This technique made it p ossible to monitor the thermal profile of the catalytic bed and the gas/sol id heat distribution, following its changes with residence time and reagent concentration. Furthermore, it allowed the diffusion limits to be estimate d as a function of the initial ratio between total and partial oxidation of methane. The surface temperature profile was found to be very dependent on the catalyst composition and controlled by the Ni oxidation. For the refor ming reactions the outlet composition was compared with the data at equilib rium, calculated at the outlet surface temperature in all reaction conditio ns. (C) 2001 Elsevier Science B.V. All rights reserved.