In this work a compact catalytic reactor was set-up for the ATR of CH4 as natural gas surrogate. Structured catalysts (commercial honeycomb and foam monoliths) performances in CH4 processing were studied. In reactor design, great attention was paid to the thermal integration, in order to obtain a total self-sustainability of the process avoiding additional external heat sources, so improving the plant compactness. Through a heat exchange system integrated in the reactor, water and air stream are preheated by exploiting the heat from exhaust stream, allowing to feed reactants at room temperature and cooling product stream up to a temperature suitable for further purification stages (Water Gas Shift, Preferential Oxidation). In order to have a very comprehensive process analysis, temperatures and composition were monitored in 6 point along the catalytic bed. The influence of catalytic system geometry and the thermal conductivity in the process performances were analyzed. Preliminary tests showed high thermal system efficiency, with a good hydrocarbon conversion at the selected operating condition for both catalyst typologies. The stream mixing along the catalytic volume appeared a crucial issue in order to increase hydrocarbon conversion and thus hydrogen yield: to obtain a chaotic reaction stream flux along catalytic bed allows to reduce temperature and composition radial gradients, and as a consequence the system quickly approach to thermodynamic equilibrium. On the other hand, continuous catalytic bed improves conductive heat transfer mechanisms, resulting in very flat thermal profiles. (C) 2013 Elsevier B.V. All rights reserved.