CH4 decomposition using catalyst pellets prepared from red mud and calcium carbide slag under fluidization for the production of H2 and carbon-based anode materials

H 2 and solid carbon are available through the CH 4 decomposition with Fe-based catalysts. Red mud is a solid waste containing lots of Fe 2 O 3 . In this work, the CeO 2 -doped solid waste-based catalyst pellets were prepared by the extrusion-spheronization method using red mud and calcium carbide slag for catalytic decomposition of CH 4 . The mass ratio of red mud to calcium carbide slag was 1:3. Regeneration of catalyst pellets with carbon deposits was performed by sieving separation and steam gasification. The effects of CeO 2 , catalyst pellet diameter, fluidization velocity, ratio and type of pore forming agent (bagasse, corn cob, horsetail pine, and walnut), ratio of binder (polyvinylpyrrolidone (PVP)), and pellet calcination duration on CH 4 decomposition and regeneration of catalyst pellets were studied in a fluidized bed reactor. The electrochemical performance of the Na-ion battery using the partial solid carbon materials from CH 4 decomposition as the anode materials was evaluated. The heat and mass transfer performance of catalyst pellets in fluidized state is enhanced. The initial CH 4 conversion is 88% in the first catalysis/regeneration cycle at 850 °C with the catalyst pellet diameter of 250–425 µm, calcination duration of 60 min, corn cob addition of 3 wt%, PVP addition of 2 wt% and fluidization velocity of 0.07 m/s. The CO 2 capture by CaO in catalyst pellets during gasification boosts the residual carbon deposits removal. The reversible sodium storage capacity of the Na-ion battery using solid carbon as the carbon-based anode material is 392.0 mAh/g. The CeO 2 -doped solid waste-based catalyst pellets are beneficial to the H 2 production, high-value utilization of solid carbon, and CO 2 capture via CH 4 decomposition and regeneration process.