Modeling and Optimal Design of an Industrial-Scale Electrothermal Fixed-Bed Reactor for Methane Steam Reforming

Electrothermal reactors are key to the electrification of chemical reaction processes, with proper designs of these reactors being essential at an industrial scale. This work proposes an industrial-scale design of ohmic heating fixed-bed reactors composed of an array of flow channels separated by electrothermal alloy walls. This design shows the advantages of easy scaling-up and the use of commercial catalyst pellets. With steam methane reforming catalyzed by Ni/Al₂O₃ as the reaction system, a three-dimensional reactor model is developed to optimize this type of ohmic heating reactor. The results show that the honeycomb structure of flow channels with a channel size of 4 cm is optimal in this reaction system, as it can balance temperature distributions and methane conversion. The inlet flow velocity and heating voltage should be carefully examined to avoid excessively high hotspot temperatures. The temperature can reach 1355 K in a case with a heating voltage of 34.4 V. These ohmic heating reactors are simple yet effective and should be useful for the electrification of industrial processes.