Application of the spatially resolved sampling technique to the analysis and optimal design of a CH4-CPO reformer with honeycomb catalyst

Catalytic partial oxidation (CPO) is considered a promising technology for H2 and syngas productions in small-medium scale in energy and transportation sectors. In fact CPO can be conducted at millisecond contact time, under autothermal conditions. These features allow for the design of simple and compact reactors with fast dynamic responses and low heat capacity. However, in the inlet zone there are high temperatures which can progressively deactivate the catalyst. Aim of this thesis work is the study of a optimal reactor design where the hot-spot are minimized preventing the deactivation of the catalyst. Different strategies can be adopted to reach this objective. Firstly, the effect of the catalyst design (catalyst load and channel opening) was investigated. The results showed that increasing the channel opening and the catalyst load of a Rh-coated honeycomb monolith there were a reduction of the rate of O2 conversion (mass transfer limited) and a selective enhancement of the rate of CH4 conversion through the endothermic reactions. Therefore, the resulting temperature profile was significantly flatter. Subsequently, the effect of the inner configuration of the reactor was investigated. The experimental tests showed that the configuration with the highest heat dispersion in the frontal section of the catalytic honeycomb was characterized by important reductions of the surface inlet temperature with only a moderate loss of performance.