Innovative catalyst design for methane steam reforming intensification

The employment of structured catalysts characterized by highly conductive carriers can result in improving the heat transfer along the catalytic bed, affording high performance with a flattened radial temperature gradient. This study focused on the Steam Reforming (SR) process intensification obtained by deposing the catalyst on a Silicon Carbide (SiC) monolith (porous walls, honeycomb shape), characterized by excellent thermal conductivity and mechanical resistance. Experimental tests carried out on SiC catalytic honeycomb monolith demonstrated that the physical properties of the support resulted in a marked system performances enhancement. One of the most relevant limitation in SR processes is the difficulty in providing heat to the catalytic system in the operating high temperatures. The high thermal conductivity of the SiC allows to minimize heat transfer resistance from the heating medium to the catalytic volume and optimize the thermal management along the catalyst, so increasing the heat flux toward the reaction volume and in turn maximizing the reforming reactions rate. A further investigation evidenced that the SiC “wall flow” guarantees a better axial and radial thermal distribution, with respect to the SiC “flow through”, resulting in better catalytic activity up to a temperature reaction of 750 °C. The comparison among the performance of the structured catalysts and the commercial 57-4MQ, provided by Katalco-JM, highlights the choice of structured catalysts, which require a lower temperature outside of the reactor, increasing the process efficiency. Therefore, the catalyst optimization in chemical and engineering points of view appeared able to enlarge the steam reforming operating window. In particular, the high conductive structured catalyst allowed to obtain appreciable performances for high reactants rate and relatively low temperature, without employing noble metals based formulations.