Effects of catalyst separation in stratified-bed autothermal reforming of methanol

An investigation of the effect of catalyst separation in stratified autothermal reforming was conducted. A reactor containing two catalyst beds - a platinum group metal monolith followed by a pelletized copper-based steam reforming catalyst - was investigated under four different configurations corresponding to different distances between the catalyst beds. Heat shields were utilized in some trials to promote reactant mixing and increase radial heat transfer through the reactor. Reactor performance, as measured by conversion, hydrogen yield, and selectivity was quantified for each configuration. Results confirm that the reaction is heat transfer limited, with the short-distance, high-temperature configuration corresponding to an improved reactor performance. This was indicated by a 4–5% drop in methanol conversion as well as in the hydrogen yield and selectivity upon the addition of spacing between the catalysts. Visual inspection of the catalyst revealed suspected signs of potential degradation due to high temperatures, indicating the need for longer-duration experiments to determine the long-term effects of sustained high temperatures on catalyst performance.