(538p) Co-Generation of Hydrogen and High-Value Carbon from Methane in a Gas-Solid Fluidized-Bed Reactor

To achieve the net zero emissions in the near future (by 2050), a catalytic methane decomposition process for producing both hydrogen and high-value graphitic carbons (CH₄ → C + 2H₂) is considered promising since it can minimize greenhouse gas emissions without CO₂ capturing and storage compared to the conventional reforming technologies. The decomposition of methane over transition-metal-based catalysts proceeds at lower temperature (700 – 800 °C) compared to the non-catalytic pyrolysis (higher than 1000 °C) so high value-added carbon products such as carbon nanotubes (CNTs) can also be produced with hydrogen. The gas-solid fluidized-bed reaction (FBR) system improving heat and mass transfer effects on the catalysis can be considered as one of the best solutions for the continuous mass production of both solid carbon and gaseous hydrogen. In order to design the stable and efficient gas-solid FBR system, the physico-chemical properties of the catalysts and the fluid-dynamic behaviors that influence each other should be thoroughly studied. Therefore, we have analyzed the basic reaction characteristics of the efficient catalysts and performed the laboratory-scale cold- and hot-bed experiments for the candidate catalyst to define important the reactor design parameters. The experimental results have provided important design principles for scale-up of FBR system so a bench-scale FBR producing 5 kg_C and 1.5 kg_H2 per day has been developed.

Acknowledgement: This work was supported by the Technology Innovation Program (20010853) funded by the Ministry of Trade, Industry & Energy (MOTIE, Korea) and also conducted under framework of the research and development program of the Korea Institute of Energy Research (C2-2480).